diff --git a/.travis.yml b/.travis.yml
index 6668279015c13..7f875065f2402 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,19 +14,13 @@ addons:
 
 env:
     global:
-        - MIN_PHP=5.5.9
-        - SYMFONY_PROCESS_PHP_TEST_BINARY=~/.phpenv/versions/5.6/bin/php
+        - MIN_PHP=7.1.3
+        - SYMFONY_PROCESS_PHP_TEST_BINARY=~/.phpenv/versions/7.1/bin/php
 
 matrix:
     include:
-        # Use the newer stack for HHVM as HHVM does not support Precise anymore since a long time and so Precise has an outdated version
-        - php: hhvm-3.18
-          sudo: required
-          dist: trusty
-          group: edge
-        - php: 5.5
-        - php: 5.6
-        - php: 7.0
+        - php: 7.1.3
+        - php: 7.1
           env: deps=high
         - php: 7.1
           env: deps=low
@@ -83,11 +77,10 @@ before_install:
       echo extension = ldap.so >> $INI
       echo extension = redis.so >> $INI
       echo extension = memcached.so >> $INI
-      [[ $PHP = 5.* ]] && echo extension = mongo.so >> $INI
-      [[ $PHP = 5.* ]] && echo extension = memcache.so >> $INI
+      #echo extension = mongodb.so >> $INI
 
       # Matrix lines for intermediate PHP versions are skipped for pull requests
-      if [[ ! $deps && ! $PHP = ${MIN_PHP%.*} && ! $PHP = hhvm* && $TRAVIS_PULL_REQUEST != false ]]; then
+      if [[ ! $deps && ! $PHP = $MIN_PHP && ! $PHP = hhvm* && $TRAVIS_PULL_REQUEST != false ]]; then
           deps=skip
           skip=1
       else
@@ -96,17 +89,14 @@ before_install:
 
     - |
       # Install sigchild-enabled PHP to test the Process component on the lowest PHP matrix line
-      if [[ ! $deps && $PHP = ${MIN_PHP%.*} && ! -d php-$MIN_PHP/sapi ]]; then
-          wget http://museum.php.net/php5/php-$MIN_PHP.tar.bz2 -O - | tar -xj &&
+      if [[ ! $deps && $PHP = $MIN_PHP && ! -d php-$MIN_PHP/sapi ]]; then
+          wget http://php.net/get/php-$MIN_PHP.tar.bz2/from/this/mirror -O - | tar -xj &&
           (cd php-$MIN_PHP && ./configure --enable-sigchild --enable-pcntl && make -j2)
       fi
 
     - |
       # Install extra PHP extensions
-      if [[ ! $skip && $PHP = 5.* ]]; then
-          ([[ $deps ]] || tfold ext.symfony_debug 'cd src/Symfony/Component/Debug/Resources/ext && phpize && ./configure && make && echo extension = $(pwd)/modules/symfony_debug.so >> '"$INI") &&
-          tfold ext.apcu4 'echo yes | pecl install -f apcu-4.0.11'
-      elif [[ ! $skip && $PHP = 7.* ]]; then
+      if [[ ! $skip && $PHP = 7.* ]]; then
           tfold ext.apcu5 'echo yes | pecl install -f apcu-5.1.6'
       fi
 
@@ -172,8 +162,8 @@ install:
           else
               echo "$COMPONENTS" | parallel --gnu "tfold {} $PHPUNIT_X {}"
               tfold tty-group $PHPUNIT --group tty
-              if [[ $PHP = ${MIN_PHP%.*} ]]; then
-                  echo -e "1\\n0" | xargs -I{} bash -c "tfold src/Symfony/Component/Process.sigchild{} SYMFONY_DEPRECATIONS_HELPER=weak ENHANCE_SIGCHLD={} php-$MIN_PHP/sapi/cli/php .phpunit/phpunit-4.8/phpunit --colors=always src/Symfony/Component/Process/"
+              if [[ $PHP = $MIN_PHP ]]; then
+                  echo -e "1\\n0" | xargs -I{} bash -c "tfold src/Symfony/Component/Process.sigchild{} SYMFONY_DEPRECATIONS_HELPER=weak ENHANCE_SIGCHLD={} php-$MIN_PHP/sapi/cli/php ./phpunit --colors=always src/Symfony/Component/Process/"
               fi
           fi
       }
diff --git a/appveyor.yml b/appveyor.yml
index f6563e730a32e..db0b2d2381473 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -11,20 +11,15 @@ init:
     - SET COMPOSER_NO_INTERACTION=1
     - SET SYMFONY_DEPRECATIONS_HELPER=strict
     - SET ANSICON=121x90 (121x90)
-    - SET SYMFONY_PHPUNIT_VERSION=4.8
     - REG ADD "HKEY_CURRENT_USER\Software\Microsoft\Command Processor" /v DelayedExpansion /t REG_DWORD /d 1 /f
 
 install:
     - mkdir c:\php && cd c:\php
-    - appveyor DownloadFile https://raw.githubusercontent.com/symfony/binary-utils/master/cacert.pem
-    - appveyor DownloadFile https://github.com/symfony/binary-utils/releases/download/v0.1/php-5.5.9-nts-Win32-VC11-x86.zip
-    - 7z x php-5.5.9-nts-Win32-VC11-x86.zip -y >nul
-    - appveyor DownloadFile https://github.com/symfony/binary-utils/releases/download/v0.1/php-7.1.3-Win32-VC14-x64.zip
+    - appveyor DownloadFile https://github.com/symfony/binary-utils/releases/download/v0.1/php-7.1.3-Win32-VC14-x86.zip
+    - 7z x php-7.1.3-Win32-VC14-x86.zip -y >nul
     - cd ext
-    - appveyor DownloadFile https://github.com/symfony/binary-utils/releases/download/v0.1/php_apcu-4.0.10-5.5-nts-vc11-x86.zip
-    - 7z x php_apcu-4.0.10-5.5-nts-vc11-x86.zip -y >nul
-    - appveyor DownloadFile https://github.com/symfony/binary-utils/releases/download/v0.1/php_memcache-3.0.8-5.5-nts-vc11-x86.zip
-    - 7z x php_memcache-3.0.8-5.5-nts-vc11-x86.zip -y >nul
+    - appveyor DownloadFile https://github.com/symfony/binary-utils/releases/download/v0.1/php_apcu-5.1.8-7.1-ts-vc14-x86.zip
+    - 7z x php_apcu-5.1.8-7.1-ts-vc14-x86.zip -y >nul
     - cd ..
     - copy /Y php.ini-development php.ini-min
     - echo serialize_precision=14 >> php.ini-min
@@ -37,13 +32,11 @@ install:
     - echo extension=php_openssl.dll >> php.ini-max
     - echo extension=php_apcu.dll >> php.ini-max
     - echo apc.enable_cli=1 >> php.ini-max
-    - echo extension=php_memcache.dll >> php.ini-max
     - echo extension=php_intl.dll >> php.ini-max
     - echo extension=php_mbstring.dll >> php.ini-max
     - echo extension=php_fileinfo.dll >> php.ini-max
     - echo extension=php_pdo_sqlite.dll >> php.ini-max
     - echo extension=php_curl.dll >> php.ini-max
-    - echo curl.cainfo=c:\php\cacert.pem >> php.ini-max
     - copy /Y php.ini-max php.ini
     - cd c:\projects\symfony
     - IF NOT EXIST composer.phar (appveyor DownloadFile https://getcomposer.org/download/1.3.0/composer.phar)
@@ -56,12 +49,8 @@ install:
 
 test_script:
     - SET X=0
-    - cd c:\php && 7z x php-7.1.3-Win32-VC14-x64.zip -y >nul && copy /Y php.ini-min php.ini
-    - cd c:\projects\symfony
-    - php phpunit src\Symfony --exclude-group benchmark,intl-data || SET X=!errorlevel!
-    - cd c:\php && 7z x php-5.5.9-nts-Win32-VC11-x86.zip -y >nul && copy /Y php.ini-min php.ini
-    - cd c:\projects\symfony
     - SET SYMFONY_PHPUNIT_SKIPPED_TESTS=phpunit.skipped
+    - copy /Y c:\php\php.ini-min c:\php\php.ini
     - php phpunit src\Symfony --exclude-group benchmark,intl-data || SET X=!errorlevel!
     - copy /Y c:\php\php.ini-max c:\php\php.ini
     - php phpunit src\Symfony --exclude-group benchmark,intl-data || SET X=!errorlevel!
diff --git a/composer.json b/composer.json
index d6649b4be41ae..b4664e545dd49 100644
--- a/composer.json
+++ b/composer.json
@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "doctrine/common": "~2.4",
         "fig/link-util": "^1.0",
         "twig/twig": "~1.32|~2.2",
@@ -26,10 +26,7 @@
         "psr/log": "~1.0",
         "psr/simple-cache": "^1.0",
         "symfony/polyfill-intl-icu": "~1.0",
-        "symfony/polyfill-mbstring": "~1.0",
-        "symfony/polyfill-php56": "~1.0",
-        "symfony/polyfill-php70": "~1.0",
-        "symfony/polyfill-util": "~1.0"
+        "symfony/polyfill-mbstring": "~1.0"
     },
     "replace": {
         "symfony/asset": "self.version",
diff --git a/src/Symfony/Bridge/Doctrine/composer.json b/src/Symfony/Bridge/Doctrine/composer.json
index b89cee2e9b2af..952e6aa639cbc 100644
--- a/src/Symfony/Bridge/Doctrine/composer.json
+++ b/src/Symfony/Bridge/Doctrine/composer.json
@@ -16,29 +16,29 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "doctrine/common": "~2.4",
         "symfony/polyfill-mbstring": "~1.0"
     },
     "require-dev": {
-        "symfony/stopwatch": "~2.8|~3.0|~4.0.0",
-        "symfony/dependency-injection": "~3.3|~4.0.0",
-        "symfony/form": "^3.2.5|~4.0.0",
-        "symfony/http-kernel": "~2.8|~3.0|~4.0.0",
-        "symfony/property-access": "~2.8|~3.0|~4.0.0",
-        "symfony/property-info": "~2.8|3.0|~4.0.0",
-        "symfony/proxy-manager-bridge": "~2.8|~3.0|~4.0.0",
-        "symfony/security": "~2.8|~3.0|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0",
-        "symfony/validator": "^2.8.18|^3.2.5|~4.0.0",
-        "symfony/translation": "~2.8|~3.0|~4.0.0",
+        "symfony/stopwatch": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
+        "symfony/form": "~3.4|~4.0",
+        "symfony/http-kernel": "~3.4|~4.0",
+        "symfony/property-access": "~3.4|~4.0",
+        "symfony/property-info": "~3.4|~4.0",
+        "symfony/proxy-manager-bridge": "~3.4|~4.0",
+        "symfony/security": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0",
+        "symfony/validator": "~3.4|~4.0",
+        "symfony/translation": "~3.4|~4.0",
         "doctrine/data-fixtures": "1.0.*",
         "doctrine/dbal": "~2.4",
         "doctrine/orm": "^2.4.5"
     },
     "conflict": {
         "phpunit/phpunit": "<4.8.35|<5.4.3,>=5.0",
-        "symfony/dependency-injection": "<3.3"
+        "symfony/dependency-injection": "<3.4"
     },
     "suggest": {
         "symfony/form": "",
diff --git a/src/Symfony/Bridge/Monolog/composer.json b/src/Symfony/Bridge/Monolog/composer.json
index a7f5f85923118..0211a86469bc1 100644
--- a/src/Symfony/Bridge/Monolog/composer.json
+++ b/src/Symfony/Bridge/Monolog/composer.json
@@ -16,17 +16,17 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "monolog/monolog": "~1.19",
-        "symfony/http-kernel": "~2.8|~3.0|~4.0.0"
+        "symfony/http-kernel": "~3.4|~4.0"
     },
     "require-dev": {
-        "symfony/console": "~2.8|~3.0|~4.0.0",
-        "symfony/event-dispatcher": "~2.8|~3.0|~4.0.0",
-        "symfony/var-dumper": "~3.3|~4.0.0"
+        "symfony/console": "~3.4|~4.0",
+        "symfony/event-dispatcher": "~3.4|~4.0",
+        "symfony/var-dumper": "~3.4|~4.0"
     },
     "conflict": {
-        "symfony/http-foundation": "<3.3"
+        "symfony/http-foundation": "<3.4"
     },
     "suggest": {
         "symfony/http-kernel": "For using the debugging handlers together with the response life cycle of the HTTP kernel.",
diff --git a/src/Symfony/Bridge/ProxyManager/composer.json b/src/Symfony/Bridge/ProxyManager/composer.json
index 208a1d0669d9c..a2ea35dd182ee 100644
--- a/src/Symfony/Bridge/ProxyManager/composer.json
+++ b/src/Symfony/Bridge/ProxyManager/composer.json
@@ -16,12 +16,12 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/dependency-injection": "~2.8|~3.0|~4.0.0",
+        "php": "^7.1.3",
+        "symfony/dependency-injection": "~3.4|~4.0",
         "ocramius/proxy-manager": "~0.4|~1.0|~2.0"
     },
     "require-dev": {
-        "symfony/config": "~2.8|~3.0|~4.0.0"
+        "symfony/config": "~3.4|~4.0"
     },
     "autoload": {
         "psr-4": { "Symfony\\Bridge\\ProxyManager\\": "" },
diff --git a/src/Symfony/Bridge/Twig/composer.json b/src/Symfony/Bridge/Twig/composer.json
index d7f6af318ea0a..89780bff748b5 100644
--- a/src/Symfony/Bridge/Twig/composer.json
+++ b/src/Symfony/Bridge/Twig/composer.json
@@ -16,27 +16,27 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "twig/twig": "~1.28|~2.0"
     },
     "require-dev": {
         "fig/link-util": "^1.0",
-        "symfony/asset": "~2.8|~3.0|~4.0.0",
-        "symfony/finder": "~2.8|~3.0|~4.0.0",
-        "symfony/form": "^3.2.7|~4.0.0",
-        "symfony/http-kernel": "~3.2|~4.0.0",
+        "symfony/asset": "~3.4|~4.0",
+        "symfony/finder": "~3.4|~4.0",
+        "symfony/form": "~3.4|~4.0",
+        "symfony/http-kernel": "~3.4|~4.0",
         "symfony/polyfill-intl-icu": "~1.0",
-        "symfony/routing": "~2.8|~3.0|~4.0.0",
-        "symfony/templating": "~2.8|~3.0|~4.0.0",
-        "symfony/translation": "~2.8|~3.0|~4.0.0",
-        "symfony/yaml": "~2.8|~3.0|~4.0.0",
-        "symfony/security": "~2.8|~3.0|~4.0.0",
+        "symfony/routing": "~3.4|~4.0",
+        "symfony/templating": "~3.4|~4.0",
+        "symfony/translation": "~3.4|~4.0",
+        "symfony/yaml": "~3.4|~4.0",
+        "symfony/security": "~3.4|~4.0",
         "symfony/security-acl": "~2.8|~3.0",
-        "symfony/stopwatch": "~2.8|~3.0|~4.0.0",
-        "symfony/console": "~2.8|~3.0|~4.0.0",
-        "symfony/var-dumper": "~2.8.10|~3.1.4|~3.2|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0",
-        "symfony/web-link": "~3.3|~4.0.0"
+        "symfony/stopwatch": "~3.4|~4.0",
+        "symfony/console": "~3.4|~4.0",
+        "symfony/var-dumper": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0",
+        "symfony/web-link": "~3.4|~4.0"
     },
     "suggest": {
         "symfony/finder": "",
diff --git a/src/Symfony/Bundle/DebugBundle/composer.json b/src/Symfony/Bundle/DebugBundle/composer.json
index c0064733f76d8..ccfe8d6788e22 100644
--- a/src/Symfony/Bundle/DebugBundle/composer.json
+++ b/src/Symfony/Bundle/DebugBundle/composer.json
@@ -16,15 +16,15 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/http-kernel": "~2.8|~3.0|~4.0.0",
-        "symfony/twig-bridge": "~2.8|~3.0|~4.0.0",
-        "symfony/var-dumper": "~2.8|~3.0|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/http-kernel": "~3.4|~4.0",
+        "symfony/twig-bridge": "~3.4|~4.0",
+        "symfony/var-dumper": "~3.4|~4.0"
     },
     "require-dev": {
-        "symfony/config": "~3.3|~4.0.0",
-        "symfony/dependency-injection": "~3.3|~4.0.0",
-        "symfony/web-profiler-bundle": "~2.8|~3.0|~4.0.0"
+        "symfony/config": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
+        "symfony/web-profiler-bundle": "~3.4|~4.0"
     },
     "suggest": {
         "symfony/config": "For service container configuration",
diff --git a/src/Symfony/Bundle/FrameworkBundle/composer.json b/src/Symfony/Bundle/FrameworkBundle/composer.json
index e23aeb19cade8..1ca10ad781a70 100644
--- a/src/Symfony/Bundle/FrameworkBundle/composer.json
+++ b/src/Symfony/Bundle/FrameworkBundle/composer.json
@@ -16,44 +16,44 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "ext-xml": "*",
-        "symfony/cache": "~3.3|~4.0.0",
-        "symfony/class-loader": "~3.2",
-        "symfony/dependency-injection": "~3.3-beta2|~4.0.0",
-        "symfony/config": "~3.3|~4.0.0",
-        "symfony/event-dispatcher": "~3.3|~4.0.0",
-        "symfony/http-foundation": "~3.3|~4.0.0",
-        "symfony/http-kernel": "~3.3|~4.0.0",
+        "symfony/cache": "~3.4|~4.0",
+        "symfony/class-loader": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
+        "symfony/config": "~3.4|~4.0",
+        "symfony/event-dispatcher": "~3.4|~4.0",
+        "symfony/http-foundation": "~3.4|~4.0",
+        "symfony/http-kernel": "~3.4|~4.0",
         "symfony/polyfill-mbstring": "~1.0",
-        "symfony/filesystem": "~2.8|~3.0|~4.0.0",
-        "symfony/finder": "~2.8|~3.0|~4.0.0",
-        "symfony/routing": "~3.3|~4.0.0",
-        "symfony/stopwatch": "~2.8|~3.0|~4.0.0",
+        "symfony/filesystem": "~3.4|~4.0",
+        "symfony/finder": "~3.4|~4.0",
+        "symfony/routing": "~3.4|~4.0",
+        "symfony/stopwatch": "~3.4|~4.0",
         "doctrine/cache": "~1.0"
     },
     "require-dev": {
         "fig/link-util": "^1.0",
-        "symfony/asset": "~3.3|~4.0.0",
-        "symfony/browser-kit": "~2.8|~3.0|~4.0.0",
-        "symfony/console": "~3.3|~4.0.0",
-        "symfony/css-selector": "~2.8|~3.0|~4.0.0",
-        "symfony/dom-crawler": "~2.8|~3.0|~4.0.0",
+        "symfony/asset": "~3.4|~4.0",
+        "symfony/browser-kit": "~3.4|~4.0",
+        "symfony/console": "~3.4|~4.0",
+        "symfony/css-selector": "~3.4|~4.0",
+        "symfony/dom-crawler": "~3.4|~4.0",
         "symfony/polyfill-intl-icu": "~1.0",
-        "symfony/security": "~2.8|~3.0|~4.0.0",
-        "symfony/form": "~3.3|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0",
-        "symfony/process": "~2.8|~3.0|~4.0.0",
-        "symfony/security-core": "~3.2|~4.0.0",
-        "symfony/security-csrf": "~2.8|~3.0|~4.0.0",
-        "symfony/serializer": "~3.3|~4.0.0",
-        "symfony/translation": "~3.2|~4.0.0",
-        "symfony/templating": "~2.8|~3.0|~4.0.0",
-        "symfony/validator": "~3.3|~4.0.0",
-        "symfony/workflow": "~3.3|~4.0.0",
-        "symfony/yaml": "~3.2|~4.0.0",
-        "symfony/property-info": "~3.3|~4.0.0",
-        "symfony/web-link": "~3.3|~4.0.0",
+        "symfony/security": "~3.4|~4.0",
+        "symfony/form": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0",
+        "symfony/process": "~3.4|~4.0",
+        "symfony/security-core": "~3.4|~4.0",
+        "symfony/security-csrf": "~3.4|~4.0",
+        "symfony/serializer": "~3.4|~4.0",
+        "symfony/translation": "~3.4|~4.0",
+        "symfony/templating": "~3.4|~4.0",
+        "symfony/validator": "~3.4|~4.0",
+        "symfony/workflow": "~3.4|~4.0",
+        "symfony/yaml": "~3.4|~4.0",
+        "symfony/property-info": "~3.4|~4.0",
+        "symfony/web-link": "~3.4|~4.0",
         "doctrine/annotations": "~1.0",
         "phpdocumentor/reflection-docblock": "^3.0",
         "twig/twig": "~1.26|~2.0",
@@ -63,14 +63,14 @@
         "phpdocumentor/reflection-docblock": "<3.0",
         "phpdocumentor/type-resolver": "<0.2.0",
         "phpunit/phpunit": "<4.8.35|<5.4.3,>=5.0",
-        "symfony/asset": "<3.3",
-        "symfony/console": "<3.3",
-        "symfony/form": "<3.3",
-        "symfony/property-info": "<3.3",
-        "symfony/serializer": "<3.3",
-        "symfony/translation": "<3.2",
-        "symfony/validator": "<3.3",
-        "symfony/workflow": "<3.3"
+        "symfony/asset": "<3.4",
+        "symfony/console": "<3.4",
+        "symfony/form": "<3.4",
+        "symfony/property-info": "<3.4",
+        "symfony/serializer": "<3.4",
+        "symfony/translation": "<3.4",
+        "symfony/validator": "<3.4",
+        "symfony/workflow": "<3.4"
     },
     "suggest": {
         "ext-apcu": "For best performance of the system caches",
diff --git a/src/Symfony/Bundle/SecurityBundle/composer.json b/src/Symfony/Bundle/SecurityBundle/composer.json
index 3611b1de6e476..697bda1943fc9 100644
--- a/src/Symfony/Bundle/SecurityBundle/composer.json
+++ b/src/Symfony/Bundle/SecurityBundle/composer.json
@@ -16,35 +16,34 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/security": "~3.3|~4.0.0",
-        "symfony/dependency-injection": "~3.3-beta2|~4.0.0",
-        "symfony/http-kernel": "~3.3|~4.0.0",
-        "symfony/polyfill-php70": "~1.0"
+        "php": "^7.1.3",
+        "symfony/security": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
+        "symfony/http-kernel": "~3.4|~4.0"
     },
     "require-dev": {
-        "symfony/asset": "~2.8|~3.0|~4.0.0",
-        "symfony/browser-kit": "~2.8|~3.0|~4.0.0",
-        "symfony/console": "~3.2|~4.0.0",
-        "symfony/css-selector": "~2.8|~3.0|~4.0.0",
-        "symfony/dom-crawler": "~2.8|~3.0|~4.0.0",
-        "symfony/form": "^2.8.18|^3.2.5|~4.0.0",
-        "symfony/framework-bundle": "^3.2.8|~4.0.0",
-        "symfony/http-foundation": "~2.8|~3.0|~4.0.0",
+        "symfony/asset": "~3.4|~4.0",
+        "symfony/browser-kit": "~3.4|~4.0",
+        "symfony/console": "~3.4|~4.0",
+        "symfony/css-selector": "~3.4|~4.0",
+        "symfony/dom-crawler": "~3.4|~4.0",
+        "symfony/form": "~3.4|~4.0",
+        "symfony/framework-bundle": "~3.4|~4.0",
+        "symfony/http-foundation": "~3.4|~4.0",
         "symfony/security-acl": "~2.8|~3.0",
-        "symfony/translation": "~2.8|~3.0|~4.0.0",
-        "symfony/twig-bundle": "~2.8|~3.0|~4.0.0",
-        "symfony/twig-bridge": "~2.8|~3.0|~4.0.0",
-        "symfony/process": "~2.8|~3.0|~4.0.0",
-        "symfony/validator": "^3.2.5|~4.0.0",
-        "symfony/var-dumper": "~3.3|~4.0.0",
-        "symfony/yaml": "~2.8|~3.0|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0",
+        "symfony/translation": "~3.4|~4.0",
+        "symfony/twig-bundle": "~3.4|~4.0",
+        "symfony/twig-bridge": "~3.4|~4.0",
+        "symfony/process": "~3.4|~4.0",
+        "symfony/validator": "~3.4|~4.0",
+        "symfony/var-dumper": "~3.4|~4.0",
+        "symfony/yaml": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0",
         "doctrine/doctrine-bundle": "~1.4",
         "twig/twig": "~1.28|~2.0"
     },
     "conflict": {
-        "symfony/var-dumper": "<3.3"
+        "symfony/var-dumper": "<3.4"
     },
     "suggest": {
         "symfony/security-acl": "For using the ACL functionality of this bundle"
diff --git a/src/Symfony/Bundle/TwigBundle/composer.json b/src/Symfony/Bundle/TwigBundle/composer.json
index facbdfdb51e08..ec19e6080a463 100644
--- a/src/Symfony/Bundle/TwigBundle/composer.json
+++ b/src/Symfony/Bundle/TwigBundle/composer.json
@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "symfony/config": "~3.2",
         "symfony/twig-bridge": "^3.3",
         "symfony/http-foundation": "~2.8|~3.0",
@@ -24,21 +24,21 @@
         "twig/twig": "^1.32|^2.2"
     },
     "require-dev": {
-        "symfony/asset": "~2.8|~3.0|~4.0.0",
-        "symfony/stopwatch": "~2.8|~3.0|~4.0.0",
-        "symfony/dependency-injection": "~3.3|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0",
-        "symfony/finder": "~2.8|~3.0|~4.0.0",
-        "symfony/form": "~2.8|~3.0|~4.0.0",
-        "symfony/routing": "~2.8|~3.0|~4.0.0",
-        "symfony/templating": "~2.8|~3.0|~4.0.0",
-        "symfony/yaml": "~2.8|~3.0|~4.0.0",
-        "symfony/framework-bundle": "^3.2.8|~4.0.0",
-        "symfony/web-link": "~3.3|~4.0.0",
+        "symfony/asset": "~3.4|~4.0",
+        "symfony/stopwatch": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0",
+        "symfony/finder": "~3.4|~4.0",
+        "symfony/form": "~3.4|~4.0",
+        "symfony/routing": "~3.4|~4.0",
+        "symfony/templating": "~3.4|~4.0",
+        "symfony/yaml": "~3.4|~4.0",
+        "symfony/framework-bundle": "~3.4|~4.0",
+        "symfony/web-link": "~3.4|~4.0",
         "doctrine/annotations": "~1.0"
     },
     "conflict": {
-        "symfony/dependency-injection": "<3.3"
+        "symfony/dependency-injection": "<3.4"
     },
     "autoload": {
         "psr-4": { "Symfony\\Bundle\\TwigBundle\\": "" },
diff --git a/src/Symfony/Bundle/WebProfilerBundle/composer.json b/src/Symfony/Bundle/WebProfilerBundle/composer.json
index 789b45dc310ef..9841237066a98 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/composer.json
+++ b/src/Symfony/Bundle/WebProfilerBundle/composer.json
@@ -16,24 +16,23 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/http-kernel": "~3.2|~4.0.0",
-        "symfony/polyfill-php70": "~1.0",
-        "symfony/routing": "~2.8|~3.0|~4.0.0",
-        "symfony/twig-bridge": "~2.8|~3.0|~4.0.0",
-        "twig/twig": "~1.28|~2.0",
-        "symfony/var-dumper": "~3.3|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/http-kernel": "~3.4|~4.0",
+        "symfony/routing": "~3.4|~4.0",
+        "symfony/twig-bridge": "~3.4|~4.0",
+        "symfony/var-dumper": "~3.4|~4.0",
+        "twig/twig": "~1.28|~2.0"
     },
     "require-dev": {
-        "symfony/config": "~2.8|~3.0|~4.0.0",
-        "symfony/console": "~2.8|~3.0|~4.0.0",
-        "symfony/dependency-injection": "~3.3|~4.0.0",
-        "symfony/stopwatch": "~2.8|~3.0|~4.0.0"
+        "symfony/config": "~3.4|~4.0",
+        "symfony/console": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
+        "symfony/stopwatch": "~3.4|~4.0"
     },
     "conflict": {
-        "symfony/dependency-injection": "<3.3",
-        "symfony/event-dispatcher": "<3.2",
-        "symfony/var-dumper": "<3.3"
+        "symfony/dependency-injection": "<3.4",
+        "symfony/event-dispatcher": "<3.4",
+        "symfony/var-dumper": "<3.4"
     },
     "autoload": {
         "psr-4": { "Symfony\\Bundle\\WebProfilerBundle\\": "" },
diff --git a/src/Symfony/Bundle/WebServerBundle/composer.json b/src/Symfony/Bundle/WebServerBundle/composer.json
index b139a070a02e3..dda1c9245ffee 100644
--- a/src/Symfony/Bundle/WebServerBundle/composer.json
+++ b/src/Symfony/Bundle/WebServerBundle/composer.json
@@ -16,10 +16,10 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/console": "~2.8.8|~3.0.8|~3.1.2|~3.2|~4.0.0",
-        "symfony/http-kernel": "~2.8|~3.0|~4.0.0",
-        "symfony/process": "~2.8|~3.0|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/console": "~3.4|~4.0",
+        "symfony/http-kernel": "~3.4|~4.0",
+        "symfony/process": "~3.4|~4.0"
     },
     "autoload": {
         "psr-4": { "Symfony\\Bundle\\WebServerBundle\\": "" },
@@ -28,7 +28,7 @@
         ]
     },
     "conflict": {
-        "symfony/dependency-injection": "<3.3"
+        "symfony/dependency-injection": "<3.4"
     },
     "minimum-stability": "dev",
     "extra": {
diff --git a/src/Symfony/Component/Asset/composer.json b/src/Symfony/Component/Asset/composer.json
index adaaf36cd934b..e60d306d6d62b 100644
--- a/src/Symfony/Component/Asset/composer.json
+++ b/src/Symfony/Component/Asset/composer.json
@@ -16,14 +16,14 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "suggest": {
         "symfony/http-foundation": ""
     },
     "require-dev": {
-        "symfony/http-foundation": "~2.8|~3.0|~4.0.0",
-        "symfony/http-kernel": "~2.8|~3.0|~4.0.0"
+        "symfony/http-foundation": "~3.4|~4.0",
+        "symfony/http-kernel": "~3.4|~4.0"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Asset\\": "" },
diff --git a/src/Symfony/Component/BrowserKit/composer.json b/src/Symfony/Component/BrowserKit/composer.json
index 7bac2c117b2fa..eda8a9d7c3acd 100644
--- a/src/Symfony/Component/BrowserKit/composer.json
+++ b/src/Symfony/Component/BrowserKit/composer.json
@@ -16,12 +16,12 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/dom-crawler": "~2.8|~3.0|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/dom-crawler": "~3.4|~4.0"
     },
     "require-dev": {
-        "symfony/process": "~2.8|~3.0|~4.0.0",
-        "symfony/css-selector": "~2.8|~3.0|~4.0.0"
+        "symfony/process": "~3.4|~4.0",
+        "symfony/css-selector": "~3.4|~4.0"
     },
     "suggest": {
         "symfony/process": ""
diff --git a/src/Symfony/Component/Cache/composer.json b/src/Symfony/Component/Cache/composer.json
index 4c448dd3459f2..7a64053c4f8a3 100644
--- a/src/Symfony/Component/Cache/composer.json
+++ b/src/Symfony/Component/Cache/composer.json
@@ -20,7 +20,7 @@
         "psr/simple-cache-implementation": "1.0"
     },
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "psr/cache": "~1.0",
         "psr/log": "~1.0",
         "psr/simple-cache": "^1.0"
@@ -32,7 +32,7 @@
         "predis/predis": "~1.0"
     },
     "conflict": {
-        "symfony/var-dumper": "<3.3"
+        "symfony/var-dumper": "<3.4"
     },
     "suggest": {
         "symfony/polyfill-apcu": "For using ApcuAdapter on HHVM"
diff --git a/src/Symfony/Component/ClassLoader/composer.json b/src/Symfony/Component/ClassLoader/composer.json
index a3fa79c44211c..65f35cdb7394b 100644
--- a/src/Symfony/Component/ClassLoader/composer.json
+++ b/src/Symfony/Component/ClassLoader/composer.json
@@ -17,10 +17,10 @@
     ],
     "minimum-stability": "dev",
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "require-dev": {
-        "symfony/finder": "~2.8|~3.0|~4.0.0",
+        "symfony/finder": "~3.4|~4.0",
         "symfony/polyfill-apcu": "~1.1"
     },
     "suggest": {
diff --git a/src/Symfony/Component/Config/composer.json b/src/Symfony/Component/Config/composer.json
index 2162bc19bee24..79a7da14ffd52 100644
--- a/src/Symfony/Component/Config/composer.json
+++ b/src/Symfony/Component/Config/composer.json
@@ -16,15 +16,15 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/filesystem": "~2.8|~3.0|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/filesystem": "~3.4|~4.0"
     },
     "require-dev": {
-        "symfony/yaml": "~3.0|~4.0.0",
-        "symfony/dependency-injection": "~3.3|~4.0.0"
+        "symfony/yaml": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0"
     },
     "conflict": {
-        "symfony/dependency-injection": "<3.3"
+        "symfony/dependency-injection": "<3.4"
     },
     "suggest": {
         "symfony/yaml": "To use the yaml reference dumper"
diff --git a/src/Symfony/Component/Console/composer.json b/src/Symfony/Component/Console/composer.json
index 97bdeee548aaa..8fb9bdf7d822b 100644
--- a/src/Symfony/Component/Console/composer.json
+++ b/src/Symfony/Component/Console/composer.json
@@ -16,16 +16,16 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "symfony/polyfill-mbstring": "~1.0",
-        "symfony/debug": "~2.8|~3.0|~4.0.0"
+        "symfony/debug": "~3.4|~4.0"
     },
     "require-dev": {
-        "symfony/http-kernel": "~2.8|~3.0|~4.0.0",
-        "symfony/event-dispatcher": "~2.8|~3.0|~4.0.0",
-        "symfony/dependency-injection": "~3.3|~4.0.0",
-        "symfony/filesystem": "~2.8|~3.0|~4.0.0",
-        "symfony/process": "~2.8|~3.0|~4.0.0",
+        "symfony/http-kernel": "~3.4|~4.0",
+        "symfony/event-dispatcher": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
+        "symfony/filesystem": "~3.4|~4.0",
+        "symfony/process": "~3.4|~4.0",
         "psr/log": "~1.0"
     },
     "suggest": {
@@ -35,7 +35,7 @@
         "psr/log": "For using the console logger"
     },
     "conflict": {
-        "symfony/dependency-injection": "<3.3"
+        "symfony/dependency-injection": "<3.4"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Console\\": "" },
diff --git a/src/Symfony/Component/CssSelector/composer.json b/src/Symfony/Component/CssSelector/composer.json
index 3b54f34d3c61c..f0b165170e659 100644
--- a/src/Symfony/Component/CssSelector/composer.json
+++ b/src/Symfony/Component/CssSelector/composer.json
@@ -20,7 +20,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\CssSelector\\": "" },
diff --git a/src/Symfony/Component/Debug/composer.json b/src/Symfony/Component/Debug/composer.json
index 0277bb5760621..2e6fc173e71e2 100644
--- a/src/Symfony/Component/Debug/composer.json
+++ b/src/Symfony/Component/Debug/composer.json
@@ -16,14 +16,14 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "psr/log": "~1.0"
     },
     "conflict": {
-        "symfony/http-kernel": ">=2.3,<2.3.24|~2.4.0|>=2.5,<2.5.9|>=2.6,<2.6.2"
+        "symfony/http-kernel": "<3.4"
     },
     "require-dev": {
-        "symfony/http-kernel": "~2.8|~3.0|~4.0.0"
+        "symfony/http-kernel": "~3.4|~4.0"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Debug\\": "" },
diff --git a/src/Symfony/Component/DependencyInjection/composer.json b/src/Symfony/Component/DependencyInjection/composer.json
index 95127f64abc55..29b85343438ee 100644
--- a/src/Symfony/Component/DependencyInjection/composer.json
+++ b/src/Symfony/Component/DependencyInjection/composer.json
@@ -16,13 +16,13 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "psr/container": "^1.0"
     },
     "require-dev": {
-        "symfony/yaml": "~3.3|~4.0.0",
-        "symfony/config": "~3.3|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0"
+        "symfony/yaml": "~3.4|~4.0",
+        "symfony/config": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0"
     },
     "suggest": {
         "symfony/yaml": "",
@@ -32,9 +32,9 @@
         "symfony/proxy-manager-bridge": "Generate service proxies to lazy load them"
     },
     "conflict": {
-        "symfony/config": "<=3.3-beta1",
-        "symfony/finder": "<3.3",
-        "symfony/yaml": "<3.3"
+        "symfony/config": "<3.4",
+        "symfony/finder": "<3.4",
+        "symfony/yaml": "<3.4"
     },
     "provide": {
         "psr/container-implementation": "1.0"
diff --git a/src/Symfony/Component/DomCrawler/composer.json b/src/Symfony/Component/DomCrawler/composer.json
index cebe4e157be09..8c04c700168ae 100644
--- a/src/Symfony/Component/DomCrawler/composer.json
+++ b/src/Symfony/Component/DomCrawler/composer.json
@@ -16,11 +16,11 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "symfony/polyfill-mbstring": "~1.0"
     },
     "require-dev": {
-        "symfony/css-selector": "~2.8|~3.0|~4.0.0"
+        "symfony/css-selector": "~3.4|~4.0"
     },
     "suggest": {
         "symfony/css-selector": ""
diff --git a/src/Symfony/Component/Dotenv/composer.json b/src/Symfony/Component/Dotenv/composer.json
index 4673837b315a2..ea62967631683 100644
--- a/src/Symfony/Component/Dotenv/composer.json
+++ b/src/Symfony/Component/Dotenv/composer.json
@@ -16,10 +16,10 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "require-dev": {
-        "symfony/process": "~3.2|~4.0.0"
+        "symfony/process": "~3.4|~4.0"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Dotenv\\": "" },
diff --git a/src/Symfony/Component/EventDispatcher/composer.json b/src/Symfony/Component/EventDispatcher/composer.json
index 10c08b7fe5d04..01f206c3b734f 100644
--- a/src/Symfony/Component/EventDispatcher/composer.json
+++ b/src/Symfony/Component/EventDispatcher/composer.json
@@ -16,17 +16,17 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "require-dev": {
-        "symfony/dependency-injection": "~3.3|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0",
-        "symfony/config": "~2.8|~3.0|~4.0.0",
-        "symfony/stopwatch": "~2.8|~3.0|~4.0.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0",
+        "symfony/config": "~3.4|~4.0",
+        "symfony/stopwatch": "~3.4|~4.0",
         "psr/log": "~1.0"
     },
     "conflict": {
-        "symfony/dependency-injection": "<3.3"
+        "symfony/dependency-injection": "<3.4"
     },
     "suggest": {
         "symfony/dependency-injection": "",
diff --git a/src/Symfony/Component/ExpressionLanguage/composer.json b/src/Symfony/Component/ExpressionLanguage/composer.json
index f62dad6fa44fa..e041ea0fd7f89 100644
--- a/src/Symfony/Component/ExpressionLanguage/composer.json
+++ b/src/Symfony/Component/ExpressionLanguage/composer.json
@@ -16,8 +16,8 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/cache": "~3.1|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/cache": "~3.4|~4.0"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\ExpressionLanguage\\": "" },
diff --git a/src/Symfony/Component/Filesystem/composer.json b/src/Symfony/Component/Filesystem/composer.json
index 289d3e63913b4..bee959429f90c 100644
--- a/src/Symfony/Component/Filesystem/composer.json
+++ b/src/Symfony/Component/Filesystem/composer.json
@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Filesystem\\": "" },
diff --git a/src/Symfony/Component/Finder/composer.json b/src/Symfony/Component/Finder/composer.json
index 410d92ba3db6b..906e1a6866426 100644
--- a/src/Symfony/Component/Finder/composer.json
+++ b/src/Symfony/Component/Finder/composer.json
@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Finder\\": "" },
diff --git a/src/Symfony/Component/Form/composer.json b/src/Symfony/Component/Form/composer.json
index e5fa43030c566..f85cec9e8a88c 100644
--- a/src/Symfony/Component/Form/composer.json
+++ b/src/Symfony/Component/Form/composer.json
@@ -16,31 +16,31 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/event-dispatcher": "~2.8|~3.0|~4.0.0",
-        "symfony/intl": "^2.8.18|^3.2.5|~4.0.0",
-        "symfony/options-resolver": "~2.8|~3.0|~4.0.0",
+        "php": "^7.1.3",
+        "symfony/event-dispatcher": "~3.4|~4.0",
+        "symfony/intl": "~3.4|~4.0",
+        "symfony/options-resolver": "~3.4|~4.0",
         "symfony/polyfill-mbstring": "~1.0",
-        "symfony/property-access": "~2.8|~3.0|~4.0.0"
+        "symfony/property-access": "~3.4|~4.0"
     },
     "require-dev": {
         "doctrine/collections": "~1.0",
-        "symfony/validator": "^2.8.18|^3.2.5|~4.0.0",
-        "symfony/dependency-injection": "~3.3|~4.0.0",
-        "symfony/config": "~2.7|~3.0|~4.0.0",
-        "symfony/http-foundation": "~2.8|~3.0|~4.0.0",
-        "symfony/http-kernel": "~2.8|~3.0|~4.0.0",
-        "symfony/security-csrf": "~2.8|~3.0|~4.0.0",
-        "symfony/translation": "~2.8|~3.0|~4.0.0",
-        "symfony/var-dumper": "~3.3|~4.0.0"
+        "symfony/validator": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
+        "symfony/config": "~3.4|~4.0",
+        "symfony/http-foundation": "~3.4|~4.0",
+        "symfony/http-kernel": "~3.4|~4.0",
+        "symfony/security-csrf": "~3.4|~4.0",
+        "symfony/translation": "~3.4|~4.0",
+        "symfony/var-dumper": "~3.4|~4.0"
     },
     "conflict": {
         "phpunit/phpunit": "<4.8.35|<5.4.3,>=5.0",
-        "symfony/dependency-injection": "<3.3",
-        "symfony/doctrine-bridge": "<2.7",
-        "symfony/framework-bundle": "<2.7",
-        "symfony/twig-bridge": "<2.7",
-        "symfony/var-dumper": "<3.3"
+        "symfony/dependency-injection": "<3.4",
+        "symfony/doctrine-bridge": "<3.4",
+        "symfony/framework-bundle": "<3.4",
+        "symfony/twig-bridge": "<3.4",
+        "symfony/var-dumper": "<3.4"
     },
     "suggest": {
         "symfony/validator": "For form validation.",
diff --git a/src/Symfony/Component/HttpFoundation/composer.json b/src/Symfony/Component/HttpFoundation/composer.json
index fe66703fdd68c..fb84f3e9931e9 100644
--- a/src/Symfony/Component/HttpFoundation/composer.json
+++ b/src/Symfony/Component/HttpFoundation/composer.json
@@ -16,11 +16,11 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "symfony/polyfill-mbstring": "~1.1"
     },
     "require-dev": {
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0"
+        "symfony/expression-language": "~3.4|~4.0"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\HttpFoundation\\": "" },
diff --git a/src/Symfony/Component/HttpKernel/Kernel.php b/src/Symfony/Component/HttpKernel/Kernel.php
index 02fe035c0b29d..ae31a46fc985f 100644
--- a/src/Symfony/Component/HttpKernel/Kernel.php
+++ b/src/Symfony/Component/HttpKernel/Kernel.php
@@ -63,7 +63,7 @@ abstract class Kernel implements KernelInterface, TerminableInterface
 
     const VERSION = '4.0.0-DEV';
     const VERSION_ID = 40000;
-    const MAJOR_VERSION = 4;
+    const MAJOR_VERSION = 0;
     const MINOR_VERSION = 0;
     const RELEASE_VERSION = 0;
     const EXTRA_VERSION = 'DEV';
diff --git a/src/Symfony/Component/HttpKernel/composer.json b/src/Symfony/Component/HttpKernel/composer.json
index 53376a61db667..3c2e47b5a613a 100644
--- a/src/Symfony/Component/HttpKernel/composer.json
+++ b/src/Symfony/Component/HttpKernel/composer.json
@@ -16,34 +16,34 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/event-dispatcher": "~2.8|~3.0|~4.0.0",
-        "symfony/http-foundation": "~3.3|~4.0.0",
-        "symfony/debug": "~2.8|~3.0|~4.0.0",
+        "php": "^7.1.3",
+        "symfony/event-dispatcher": "~3.4|~4.0",
+        "symfony/http-foundation": "~3.4|~4.0",
+        "symfony/debug": "~3.4|~4.0",
         "psr/log": "~1.0"
     },
     "require-dev": {
-        "symfony/browser-kit": "~2.8|~3.0|~4.0.0",
-        "symfony/class-loader": "~2.8|~3.0",
-        "symfony/config": "~2.8|~3.0|~4.0.0",
-        "symfony/console": "~2.8|~3.0|~4.0.0",
-        "symfony/css-selector": "~2.8|~3.0|~4.0.0",
-        "symfony/dependency-injection": "~3.3|~4.0.0",
-        "symfony/dom-crawler": "~2.8|~3.0|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0",
-        "symfony/finder": "~2.8|~3.0|~4.0.0",
-        "symfony/process": "~2.8|~3.0|~4.0.0",
-        "symfony/routing": "~2.8|~3.0|~4.0.0",
-        "symfony/stopwatch": "~2.8|~3.0|~4.0.0",
-        "symfony/templating": "~2.8|~3.0|~4.0.0",
-        "symfony/translation": "~2.8|~3.0|~4.0.0",
-        "symfony/var-dumper": "~3.3|~4.0.0",
+        "symfony/browser-kit": "~3.4|~4.0",
+        "symfony/class-loader": "~3.4|~4.0",
+        "symfony/config": "~3.4|~4.0",
+        "symfony/console": "~3.4|~4.0",
+        "symfony/css-selector": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
+        "symfony/dom-crawler": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0",
+        "symfony/finder": "~3.4|~4.0",
+        "symfony/process": "~3.4|~4.0",
+        "symfony/routing": "~3.4|~4.0",
+        "symfony/stopwatch": "~3.4|~4.0",
+        "symfony/templating": "~3.4|~4.0",
+        "symfony/translation": "~3.4|~4.0",
+        "symfony/var-dumper": "~3.4|~4.0",
         "psr/cache": "~1.0"
     },
     "conflict": {
-        "symfony/config": "<2.8",
-        "symfony/dependency-injection": "<3.3",
-        "symfony/var-dumper": "<3.3"
+        "symfony/config": "<3.4",
+        "symfony/dependency-injection": "<3.4",
+        "symfony/var-dumper": "<3.4"
     },
     "suggest": {
         "symfony/browser-kit": "",
diff --git a/src/Symfony/Component/Inflector/composer.json b/src/Symfony/Component/Inflector/composer.json
index 0f88a6c6295da..ebec32fadd30f 100644
--- a/src/Symfony/Component/Inflector/composer.json
+++ b/src/Symfony/Component/Inflector/composer.json
@@ -23,7 +23,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Inflector\\": "" },
diff --git a/src/Symfony/Component/Intl/composer.json b/src/Symfony/Component/Intl/composer.json
index a1a1e93204552..eb1cde0671ee3 100644
--- a/src/Symfony/Component/Intl/composer.json
+++ b/src/Symfony/Component/Intl/composer.json
@@ -24,11 +24,11 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "symfony/polyfill-intl-icu": "~1.0"
     },
     "require-dev": {
-        "symfony/filesystem": "~2.8|~3.0|~4.0.0"
+        "symfony/filesystem": "~3.4|~4.0"
     },
     "suggest": {
         "ext-intl": "to use the component with locales other than \"en\""
diff --git a/src/Symfony/Component/Ldap/composer.json b/src/Symfony/Component/Ldap/composer.json
index 21d08167acc03..9a45391ae6f86 100644
--- a/src/Symfony/Component/Ldap/composer.json
+++ b/src/Symfony/Component/Ldap/composer.json
@@ -16,9 +16,8 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/polyfill-php56": "~1.0",
-        "symfony/options-resolver": "~2.8|~3.0|~4.0.0",
+        "php": "^7.1.3",
+        "symfony/options-resolver": "~3.4|~4.0",
         "ext-ldap": "*"
     },
     "autoload": {
diff --git a/src/Symfony/Component/OptionsResolver/composer.json b/src/Symfony/Component/OptionsResolver/composer.json
index 8f8ba964a2148..ec764e644fc2c 100644
--- a/src/Symfony/Component/OptionsResolver/composer.json
+++ b/src/Symfony/Component/OptionsResolver/composer.json
@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\OptionsResolver\\": "" },
diff --git a/src/Symfony/Component/Process/composer.json b/src/Symfony/Component/Process/composer.json
index df2bce0a1bed6..08e8b5a80dbfe 100644
--- a/src/Symfony/Component/Process/composer.json
+++ b/src/Symfony/Component/Process/composer.json
@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Process\\": "" },
diff --git a/src/Symfony/Component/PropertyAccess/composer.json b/src/Symfony/Component/PropertyAccess/composer.json
index 01c3a8a0c9fe7..94a7fd04251c1 100644
--- a/src/Symfony/Component/PropertyAccess/composer.json
+++ b/src/Symfony/Component/PropertyAccess/composer.json
@@ -16,12 +16,11 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/polyfill-php70": "~1.0",
-        "symfony/inflector": "~3.1|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/inflector": "~3.4|~4.0"
     },
     "require-dev": {
-        "symfony/cache": "~3.1|~4.0.0"
+        "symfony/cache": "~3.4|~4.0"
     },
     "suggest": {
         "psr/cache-implementation": "To cache access methods."
diff --git a/src/Symfony/Component/PropertyInfo/composer.json b/src/Symfony/Component/PropertyInfo/composer.json
index 1d5cd2b830e33..4050c8e1598c8 100644
--- a/src/Symfony/Component/PropertyInfo/composer.json
+++ b/src/Symfony/Component/PropertyInfo/composer.json
@@ -23,20 +23,20 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/inflector": "~3.1|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/inflector": "~3.4|~4.0"
     },
     "require-dev": {
-        "symfony/serializer": "~2.8|~3.0|~4.0.0",
-        "symfony/cache": "~3.1|~4.0.0",
-        "symfony/dependency-injection": "~3.3|~4.0.0",
+        "symfony/serializer": "~3.4|~4.0",
+        "symfony/cache": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
         "phpdocumentor/reflection-docblock": "^3.0",
         "doctrine/annotations": "~1.0"
     },
     "conflict": {
         "phpdocumentor/reflection-docblock": "<3.0",
         "phpdocumentor/type-resolver": "<0.2.0",
-        "symfony/dependency-injection": "<3.3"
+        "symfony/dependency-injection": "<3.4"
     },
     "suggest": {
         "psr/cache-implementation": "To cache results",
diff --git a/src/Symfony/Component/Routing/composer.json b/src/Symfony/Component/Routing/composer.json
index 33d4d711f0e89..dc3d53ca32d04 100644
--- a/src/Symfony/Component/Routing/composer.json
+++ b/src/Symfony/Component/Routing/composer.json
@@ -16,22 +16,22 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "require-dev": {
-        "symfony/config": "~2.8|~3.0|~4.0.0",
-        "symfony/http-foundation": "~2.8|~3.0|~4.0.0",
-        "symfony/yaml": "~3.3|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0",
-        "symfony/dependency-injection": "~3.3|~4.0.0",
+        "symfony/config": "~3.4|~4.0",
+        "symfony/http-foundation": "~3.4|~4.0",
+        "symfony/yaml": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
         "doctrine/annotations": "~1.0",
         "doctrine/common": "~2.2",
         "psr/log": "~1.0"
     },
     "conflict": {
-        "symfony/config": "<2.8",
-        "symfony/dependency-injection": "<3.3",
-        "symfony/yaml": "<3.3"
+        "symfony/config": "<3.4",
+        "symfony/dependency-injection": "<3.4",
+        "symfony/yaml": "<3.4"
     },
     "suggest": {
         "symfony/http-foundation": "For using a Symfony Request object",
diff --git a/src/Symfony/Component/Security/Core/composer.json b/src/Symfony/Component/Security/Core/composer.json
index c7271f9bd6feb..de972a1ddf5f9 100644
--- a/src/Symfony/Component/Security/Core/composer.json
+++ b/src/Symfony/Component/Security/Core/composer.json
@@ -16,15 +16,14 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/polyfill-php56": "~1.0"
+        "php": "^7.1.3"
     },
     "require-dev": {
-        "symfony/event-dispatcher": "~2.8|~3.0|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0",
-        "symfony/http-foundation": "~2.8|~3.0|~4.0.0",
-        "symfony/ldap": "~3.1|~4.0.0",
-        "symfony/validator": "^2.8.18|^3.2.5|~4.0.0",
+        "symfony/event-dispatcher": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0",
+        "symfony/http-foundation": "~3.4|~4.0",
+        "symfony/ldap": "~3.4|~4.0",
+        "symfony/validator": "~3.4|~4.0",
         "psr/log": "~1.0"
     },
     "suggest": {
diff --git a/src/Symfony/Component/Security/Csrf/composer.json b/src/Symfony/Component/Security/Csrf/composer.json
index 87da31ffde31b..ee102a3c1fc49 100644
--- a/src/Symfony/Component/Security/Csrf/composer.json
+++ b/src/Symfony/Component/Security/Csrf/composer.json
@@ -16,13 +16,11 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/polyfill-php56": "~1.0",
-        "symfony/polyfill-php70": "~1.0",
-        "symfony/security-core": "~2.8|~3.0|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/security-core": "~3.4|~4.0"
     },
     "require-dev": {
-        "symfony/http-foundation": "~2.8|~3.0|~4.0.0"
+        "symfony/http-foundation": "~3.4|~4.0"
     },
     "suggest": {
         "symfony/http-foundation": "For using the class SessionTokenStorage."
diff --git a/src/Symfony/Component/Security/Guard/composer.json b/src/Symfony/Component/Security/Guard/composer.json
index 85f622e1137a0..194eb6cf7e3b2 100644
--- a/src/Symfony/Component/Security/Guard/composer.json
+++ b/src/Symfony/Component/Security/Guard/composer.json
@@ -16,9 +16,9 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/security-core": "~2.8|~3.0|~4.0.0",
-        "symfony/security-http": "~3.1|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/security-core": "~3.4|~4.0",
+        "symfony/security-http": "~3.4|~4.0"
     },
     "require-dev": {
         "psr/log": "~1.0"
diff --git a/src/Symfony/Component/Security/Http/composer.json b/src/Symfony/Component/Security/Http/composer.json
index 3171fb1980ca5..c4b7a605f90a3 100644
--- a/src/Symfony/Component/Security/Http/composer.json
+++ b/src/Symfony/Component/Security/Http/composer.json
@@ -16,18 +16,16 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/security-core": "~3.2|~4.0.0",
-        "symfony/event-dispatcher": "~2.8|~3.0|~4.0.0",
-        "symfony/http-foundation": "~2.8|~3.0|~4.0.0",
-        "symfony/http-kernel": "~3.3|~4.0.0",
-        "symfony/polyfill-php56": "~1.0",
-        "symfony/polyfill-php70": "~1.0",
-        "symfony/property-access": "~2.8|~3.0|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/security-core": "~3.4|~4.0",
+        "symfony/event-dispatcher": "~3.4|~4.0",
+        "symfony/http-foundation": "~3.4|~4.0",
+        "symfony/http-kernel": "~3.4|~4.0",
+        "symfony/property-access": "~3.4|~4.0"
     },
     "require-dev": {
-        "symfony/routing": "~2.8|~3.0|~4.0.0",
-        "symfony/security-csrf": "~2.8|~3.0|~4.0.0",
+        "symfony/routing": "~3.4|~4.0",
+        "symfony/security-csrf": "~3.4|~4.0",
         "psr/log": "~1.0"
     },
     "suggest": {
diff --git a/src/Symfony/Component/Security/composer.json b/src/Symfony/Component/Security/composer.json
index 9c1146f2acc4d..3b2bb564e9ae9 100644
--- a/src/Symfony/Component/Security/composer.json
+++ b/src/Symfony/Component/Security/composer.json
@@ -16,14 +16,11 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/event-dispatcher": "~2.8|~3.0|~4.0.0",
-        "symfony/http-foundation": "~2.8|~3.0|~4.0.0",
-        "symfony/http-kernel": "~3.3|~4.0.0",
-        "symfony/polyfill-php56": "~1.0",
-        "symfony/polyfill-php70": "~1.0",
-        "symfony/polyfill-util": "~1.0",
-        "symfony/property-access": "~2.8|~3.0|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/event-dispatcher": "~3.4|~4.0",
+        "symfony/http-foundation": "~3.4|~4.0",
+        "symfony/http-kernel": "~3.4|~4.0",
+        "symfony/property-access": "~3.4|~4.0"
     },
     "replace": {
         "symfony/security-core": "self.version",
@@ -32,12 +29,12 @@
         "symfony/security-http": "self.version"
     },
     "require-dev": {
-        "symfony/finder": "~2.8|~3.0|~4.0.0",
+        "symfony/finder": "~3.4|~4.0",
         "symfony/polyfill-intl-icu": "~1.0",
-        "symfony/routing": "~2.8|~3.0|~4.0.0",
-        "symfony/validator": "^2.8.18|^3.2.5|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0",
-        "symfony/ldap": "~3.1|~4.0.0",
+        "symfony/routing": "~3.4|~4.0",
+        "symfony/validator": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0",
+        "symfony/ldap": "~3.4|~4.0",
         "psr/log": "~1.0"
     },
     "suggest": {
diff --git a/src/Symfony/Component/Serializer/composer.json b/src/Symfony/Component/Serializer/composer.json
index fe91bc70bc432..d7955fcf4cbfc 100644
--- a/src/Symfony/Component/Serializer/composer.json
+++ b/src/Symfony/Component/Serializer/composer.json
@@ -16,25 +16,25 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "require-dev": {
-        "symfony/yaml": "~3.3|~4.0.0",
-        "symfony/config": "~2.8|~3.0|~4.0.0",
-        "symfony/property-access": "~2.8|~3.0|~4.0.0",
-        "symfony/http-foundation": "~2.8|~3.0|~4.0.0",
-        "symfony/cache": "~3.1|~4.0.0",
-        "symfony/property-info": "~3.1|~4.0.0",
+        "symfony/yaml": "~3.4|~4.0",
+        "symfony/config": "~3.4|~4.0",
+        "symfony/property-access": "~3.4|~4.0",
+        "symfony/http-foundation": "~3.4|~4.0",
+        "symfony/cache": "~3.4|~4.0",
+        "symfony/property-info": "~3.4|~4.0",
         "doctrine/annotations": "~1.0",
-        "symfony/dependency-injection": "~3.2|~4.0.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
         "doctrine/cache": "~1.0",
         "phpdocumentor/reflection-docblock": "~3.0"
     },
     "conflict": {
-        "symfony/dependency-injection": "<3.2",
-        "symfony/property-access": ">=3.0,<3.0.4|>=2.8,<2.8.4",
-        "symfony/property-info": "<3.1",
-        "symfony/yaml": "<3.3"
+        "symfony/dependency-injection": "<3.4",
+        "symfony/property-access": "<3.4",
+        "symfony/property-info": "<3.4",
+        "symfony/yaml": "<3.4"
     },
     "suggest": {
         "psr/cache-implementation": "For using the metadata cache.",
diff --git a/src/Symfony/Component/Stopwatch/composer.json b/src/Symfony/Component/Stopwatch/composer.json
index be5a2b16a9869..9f7f9675c45ec 100644
--- a/src/Symfony/Component/Stopwatch/composer.json
+++ b/src/Symfony/Component/Stopwatch/composer.json
@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Stopwatch\\": "" },
diff --git a/src/Symfony/Component/Templating/composer.json b/src/Symfony/Component/Templating/composer.json
index 85ebba399b790..a64a3ed9774b9 100644
--- a/src/Symfony/Component/Templating/composer.json
+++ b/src/Symfony/Component/Templating/composer.json
@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "require-dev": {
         "psr/log": "~1.0"
diff --git a/src/Symfony/Component/Translation/composer.json b/src/Symfony/Component/Translation/composer.json
index 92d680e832352..046ca173fa31a 100644
--- a/src/Symfony/Component/Translation/composer.json
+++ b/src/Symfony/Component/Translation/composer.json
@@ -16,18 +16,18 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "symfony/polyfill-mbstring": "~1.0"
     },
     "require-dev": {
-        "symfony/config": "~2.8|~3.0|~4.0.0",
-        "symfony/intl": "^2.8.18|^3.2.5|~4.0.0",
-        "symfony/yaml": "~3.3|~4.0.0",
+        "symfony/config": "~3.4|~4.0",
+        "symfony/intl": "~3.4|~4.0",
+        "symfony/yaml": "~3.4|~4.0",
         "psr/log": "~1.0"
     },
     "conflict": {
-        "symfony/config": "<2.8",
-        "symfony/yaml": "<3.3"
+        "symfony/config": "<3.4",
+        "symfony/yaml": "<3.4"
     },
     "suggest": {
         "symfony/config": "",
diff --git a/src/Symfony/Component/Validator/composer.json b/src/Symfony/Component/Validator/composer.json
index b84fff2b4aead..a51e9cad1a4d1 100644
--- a/src/Symfony/Component/Validator/composer.json
+++ b/src/Symfony/Component/Validator/composer.json
@@ -16,26 +16,26 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "symfony/polyfill-mbstring": "~1.0",
-        "symfony/translation": "~2.8|~3.0|~4.0.0"
+        "symfony/translation": "~3.4|~4.0"
     },
     "require-dev": {
-        "symfony/http-foundation": "~2.8|~3.0|~4.0.0",
-        "symfony/intl": "^2.8.18|^3.2.5|~4.0.0",
-        "symfony/yaml": "~3.3|~4.0.0",
-        "symfony/config": "~2.8|~3.0|~4.0.0",
-        "symfony/dependency-injection": "~3.3|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0",
-        "symfony/cache": "~3.1|~4.0.0",
+        "symfony/http-foundation": "~3.4|~4.0",
+        "symfony/intl": "~3.4|~4.0",
+        "symfony/yaml": "~3.4|~4.0",
+        "symfony/config": "~3.4|~4.0",
+        "symfony/dependency-injection": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0",
+        "symfony/cache": "~3.4|~4.0",
         "doctrine/annotations": "~1.0",
         "doctrine/cache": "~1.0",
         "egulias/email-validator": "^1.2.8|~2.0"
     },
     "conflict": {
         "phpunit/phpunit": "<4.8.35|<5.4.3,>=5.0",
-        "symfony/dependency-injection": "<3.3",
-        "symfony/yaml": "<3.3"
+        "symfony/dependency-injection": "<3.4",
+        "symfony/yaml": "<3.4"
     },
     "suggest": {
         "psr/cache-implementation": "For using the metadata cache.",
diff --git a/src/Symfony/Component/VarDumper/composer.json b/src/Symfony/Component/VarDumper/composer.json
index 7b0e5ca173fcb..fcd3b3bb3c96d 100644
--- a/src/Symfony/Component/VarDumper/composer.json
+++ b/src/Symfony/Component/VarDumper/composer.json
@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "symfony/polyfill-mbstring": "~1.0"
     },
     "require-dev": {
diff --git a/src/Symfony/Component/WebLink/composer.json b/src/Symfony/Component/WebLink/composer.json
index 6b8575800b9d7..d1be20177d6bd 100644
--- a/src/Symfony/Component/WebLink/composer.json
+++ b/src/Symfony/Component/WebLink/composer.json
@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
+        "php": "^7.1.3",
         "fig/link-util": "^1.0",
         "psr/link": "^1.0"
     },
@@ -24,9 +24,9 @@
         "symfony/http-kernel": ""
     },
     "require-dev": {
-        "symfony/event-dispatcher": "^2.8|^3.0|~4.0.0",
-        "symfony/http-foundation": "^2.8|^3.0|~4.0.0",
-        "symfony/http-kernel": "^2.8|^3.0|~4.0.0"
+        "symfony/event-dispatcher": "~3.4|~4.0",
+        "symfony/http-foundation": "~3.4|~4.0",
+        "symfony/http-kernel": "~3.4|~4.0"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\WebLink\\": "" },
diff --git a/src/Symfony/Component/Workflow/composer.json b/src/Symfony/Component/Workflow/composer.json
index 3583c4a4afac2..0c78dcd5a8a52 100644
--- a/src/Symfony/Component/Workflow/composer.json
+++ b/src/Symfony/Component/Workflow/composer.json
@@ -20,15 +20,15 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9",
-        "symfony/property-access": "~2.3|~3.0|~4.0.0"
+        "php": "^7.1.3",
+        "symfony/property-access": "~3.4|~4.0"
     },
     "require-dev": {
         "psr/log": "~1.0",
-        "symfony/dependency-injection": "~2.8|~3.0|~4.0.0",
-        "symfony/event-dispatcher": "~2.1|~3.0|~4.0.0",
-        "symfony/expression-language": "~2.8|~3.0|~4.0.0",
-        "symfony/security-core": "~2.8|~3.0|~4.0.0"
+        "symfony/dependency-injection": "~3.4|~4.0",
+        "symfony/event-dispatcher": "~3.4|~4.0",
+        "symfony/expression-language": "~3.4|~4.0",
+        "symfony/security-core": "~3.4|~4.0"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Workflow\\": "" }
diff --git a/src/Symfony/Component/Yaml/composer.json b/src/Symfony/Component/Yaml/composer.json
index ae7d73f80ab23..bbf84393497c9 100644
--- a/src/Symfony/Component/Yaml/composer.json
+++ b/src/Symfony/Component/Yaml/composer.json
@@ -16,10 +16,10 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": "^7.1.3"
     },
     "require-dev": {
-        "symfony/console": "~2.8|~3.0|~4.0.0"
+        "symfony/console": "~3.4|~4.0"
     },
     "suggest": {
         "symfony/console": "For validating YAML files using the lint command"