diff --git a/jenkins-client/pom.xml b/jenkins-client/pom.xml
index 2cbc3df9..ee0713d2 100644
--- a/jenkins-client/pom.xml
+++ b/jenkins-client/pom.xml
@@ -103,15 +103,22 @@
       <groupId>org.jenkins-ci.main</groupId>
       <artifactId>jenkins-test-harness</artifactId>
       <scope>test</scope>
+      <exclusions>
+        <exclusion>
+          <artifactId>junit</artifactId>
+          <groupId>junit</groupId>
+        </exclusion>
+      </exclusions>
     </dependency>
     <dependency>
       <groupId>org.assertj</groupId>
       <artifactId>assertj-core</artifactId>
       <scope>test</scope>
     </dependency>
+
     <dependency>
-      <groupId>xerces</groupId>
-      <artifactId>xmlParserAPIs</artifactId>
+      <groupId>xml-apis</groupId>
+      <artifactId>xml-apis</artifactId>
     </dependency>
   </dependencies>
 
diff --git a/jenkins-client/src/test/java/com/offbytwo/jenkins/client/util/EncodingUtilsTest.java b/jenkins-client/src/test/java/com/offbytwo/jenkins/client/util/EncodingUtilsTest.java
index 358ac7f5..2c890d59 100644
--- a/jenkins-client/src/test/java/com/offbytwo/jenkins/client/util/EncodingUtilsTest.java
+++ b/jenkins-client/src/test/java/com/offbytwo/jenkins/client/util/EncodingUtilsTest.java
@@ -5,7 +5,7 @@
  */
 package com.offbytwo.jenkins.client.util;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -14,51 +14,51 @@
  *
  *  @author Karl Heinz Marbaise
  */
-public class EncodingUtilsTest {
+class EncodingUtilsTest {
 
     @Test
-    public void encodeShouldReturnEncodedDoubleQuoteAndSpace() {
+    void encodeShouldReturnEncodedDoubleQuoteAndSpace() {
         String result = EncodingUtils.encode("!\"& ");
         assertThat(result).isEqualTo("%21%22%26+");
     }
 
     @Test
-    public void encodeShouldReturnNotEncodeSafeChars() {
+    void encodeShouldReturnNotEncodeSafeChars() {
         String result = EncodingUtils.encode("-._~!$'()*,;&=@:+");
         assertThat(result).isEqualTo("-._%7E%21%24%27%28%29*%2C%3B%26%3D%40%3A%2B");
     }
     @Test
-    public void encodeShouldReturnNotEncodeAlpha() {
+    void encodeShouldReturnNotEncodeAlpha() {
         String result = EncodingUtils.encode("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789");
         assertThat(result).isEqualTo("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789");
     }
 
     @Test
-    public void encodeShouldReturnEncodingUmlautAndOthers() {
+    void encodeShouldReturnEncodingUmlautAndOthers() {
         String result = EncodingUtils.encode("äöü#{}");
         assertThat(result).isEqualTo("%C3%A4%C3%B6%C3%BC%23%7B%7D");
     }
 
     @Test
-    public void encodeParamShouldReturnEncodedExclamationMarkDoubleQuoteAmpersampSpace() {
+    void encodeParamShouldReturnEncodedExclamationMarkDoubleQuoteAmpersampSpace() {
         String result = EncodingUtils.formParameter("!\"& ");
         assertThat(result).isEqualTo("%21%22%26+");
     }
 
     @Test
-    public void encodeParamShouldReturnNotEncodeSafeChars() {
+    void encodeParamShouldReturnNotEncodeSafeChars() {
         String result = EncodingUtils.formParameter("-_.*");
         assertThat(result).isEqualTo("-_.*");
     }
 
     @Test
-    public void encodeParamShouldReturnEncodedUmlautAndOthers() {
+    void encodeParamShouldReturnEncodedUmlautAndOthers() {
         String result = EncodingUtils.formParameter("äöü#{}");
         assertThat(result).isEqualTo("%C3%A4%C3%B6%C3%BC%23%7B%7D");
     }
 
     @Test
-    public void encodeParamShouldReturnEncodedCharacters() {
+    void encodeParamShouldReturnEncodedCharacters() {
         String result = EncodingUtils.formParameter("-._~!$'()*,;&=@:+");
         assertThat(result).isEqualTo("-._%7E%21%24%27%28%29*%2C%3B%26%3D%40%3A%2B");
     }
diff --git a/jenkins-client/src/test/java/com/offbytwo/jenkins/client/util/ResponseUtilsTest.java b/jenkins-client/src/test/java/com/offbytwo/jenkins/client/util/ResponseUtilsTest.java
index 57e001ea..77bce720 100644
--- a/jenkins-client/src/test/java/com/offbytwo/jenkins/client/util/ResponseUtilsTest.java
+++ b/jenkins-client/src/test/java/com/offbytwo/jenkins/client/util/ResponseUtilsTest.java
@@ -7,43 +7,40 @@
 
 import org.apache.http.Header;
 import org.apache.http.HttpResponse;
-import static org.junit.Assert.assertEquals;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatNullPointerException;
 import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.mock;
 
 
-
 /**
- *
  * @author Dell Green
  */
-public class ResponseUtilsTest {
-
-    
-
-    @Test
-    public void testGetJenkinsVersion() {
-        final Header header = mock(Header.class);
-        final HttpResponse response = mock(HttpResponse.class);
-        given(response.getHeaders("X-Jenkins")).willReturn(new Header[]{header});
-        given(header.getValue()).willReturn("1.234");
-        assertEquals("1.234", ResponseUtils.getJenkinsVersion(response));
-    }
-    
-    
-    @Test
-    public void testGetJenkinsVersion_NoHeader() {
-        final HttpResponse response = mock(HttpResponse.class);
-        given(response.getHeaders("X-Jenkins")).willReturn(new Header[0]);
-        assertEquals("", ResponseUtils.getJenkinsVersion(response));
-    }
-    
-    
-    @Test(expected = NullPointerException.class)
-    public void testGetJenkinsVersion_NullResponse() {
-        ResponseUtils.getJenkinsVersion(null);
-    }
+class ResponseUtilsTest {
+
+  @Test
+  void testGetJenkinsVersion() {
+    final Header header = mock(Header.class);
+    final HttpResponse response = mock(HttpResponse.class);
+    given(response.getHeaders("X-Jenkins")).willReturn(new Header[]{header});
+    given(header.getValue()).willReturn("1.234");
+    assertThat(ResponseUtils.getJenkinsVersion(response)).isEqualTo("1.234");
+  }
+
+  @Test
+  public void testGetJenkinsVersion_NoHeader() {
+    final HttpResponse response = mock(HttpResponse.class);
+    given(response.getHeaders("X-Jenkins")).willReturn(new Header[0]);
+    assertThat(ResponseUtils.getJenkinsVersion(response)).isEmpty();
+  }
+
+
+  @Test
+  void testGetJenkinsVersion_NullResponse() {
+    assertThatNullPointerException().isThrownBy(() -> ResponseUtils.getJenkinsVersion(null));
+  }
 
 
 }
\ No newline at end of file
diff --git a/jenkins-client/src/test/java/com/offbytwo/jenkins/client/util/UrlUtilsTest.java b/jenkins-client/src/test/java/com/offbytwo/jenkins/client/util/UrlUtilsTest.java
index 780600ba..6da4e39b 100644
--- a/jenkins-client/src/test/java/com/offbytwo/jenkins/client/util/UrlUtilsTest.java
+++ b/jenkins-client/src/test/java/com/offbytwo/jenkins/client/util/UrlUtilsTest.java
@@ -6,24 +6,25 @@
 package com.offbytwo.jenkins.client.util;
 
 import com.offbytwo.jenkins.model.FolderJob;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+
 import java.net.URI;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
-import org.junit.Test;
 
+import static org.assertj.core.api.Assertions.assertThat;
 
 
 /**
  *
  * @author Dell Green
  */
-public class UrlUtilsTest {
+class UrlUtilsTest {
 
     
 
     @Test
-    public void testToBaseUrl_NullFolderJob() {
-        assertEquals("/", UrlUtils.toBaseUrl(null));
+    void testToBaseUrl_NullFolderJob() {
+        assertThat(UrlUtils.toBaseUrl(null)).isEqualTo("/");
     }
 
     @Test
diff --git a/jenkins-client/src/test/java/com/offbytwo/jenkins/integration/FolderTestsIT.java b/jenkins-client/src/test/java/com/offbytwo/jenkins/integration/FolderTestsIT.java
index 098102c0..53d2260b 100644
--- a/jenkins-client/src/test/java/com/offbytwo/jenkins/integration/FolderTestsIT.java
+++ b/jenkins-client/src/test/java/com/offbytwo/jenkins/integration/FolderTestsIT.java
@@ -8,13 +8,11 @@
 import java.util.Optional;
 import java.util.Vector;
 
+import jdk.nashorn.internal.ir.annotations.Ignore;
 import jenkins.model.Jenkins;
 
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Ignore;
-import org.junit.Rule;
-import org.junit.Test;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
 import org.jvnet.hudson.test.JenkinsRule;
 import org.kohsuke.stapler.StaplerRequest;
 import org.kohsuke.stapler.StaplerResponse;
@@ -24,6 +22,9 @@
 import com.offbytwo.jenkins.model.FolderJob;
 import com.offbytwo.jenkins.model.JobWithDetails;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
 public class FolderTestsIT {
 
     private final String JENKINS_WITH_DETAILS_TEST_JOB = "build_with_details";
@@ -65,20 +66,20 @@ public void setUp() throws Exception {
     public void testFolderPluginAPIs() throws Exception {
         server.createFolder("root");
         JobWithDetails root = server.getJob("root");
-        Assert.assertNotNull(root);
+        assertThat( root).isNotNull();
 
         java.util.Optional<FolderJob> rootFolder = server.getFolderJob(root);
-        Assert.assertTrue(rootFolder.isPresent());
+        assertThat( rootFolder).isPresent();
 
         server.createFolder(rootFolder.get(), "subfolder");
         JobWithDetails subfolder = server.getJob(rootFolder.get(), "subfolder");
-        Assert.assertNotNull(subfolder);
+        assertThat( subfolder).isNotNull();
 
         Optional<FolderJob> subfolderFolder = server.getFolderJob(subfolder);
-        Assert.assertTrue(subfolderFolder.isPresent());
+        assertThat( subfolderFolder).isPresent();
 
         server.deleteJob("root");
         root = server.getJob("root");
-        Assert.assertNull(root);
+        assertThat( root ).isNull();
     }
 }
diff --git a/pom.xml b/pom.xml
index f88539d9..5ad6b284 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,8 @@
   ~ Distributed under the MIT license: http://opensource.org/licenses/MIT
 -->
 
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
 
   <parent>
@@ -48,7 +49,7 @@
     <maven.compiler.showDeprecation>true</maven.compiler.showDeprecation>
     <maven.compiler.showWarnings>true</maven.compiler.showWarnings>
 
-    <asciidoctor-maven-plugin.version>2.0.0</asciidoctor-maven-plugin.version>
+    <asciidoctor-maven-plugin.version>1.5.3</asciidoctor-maven-plugin.version>
 
     <!-- Version of Jenkins to use for Integration Tests -->
     <jenkins-version>1.644</jenkins-version>
@@ -56,7 +57,8 @@
     <mockito-core.version>3.0.0</mockito-core.version>
     <commons-io.version>2.4</commons-io.version>
     <xstream.version>1.4.7-jenkins-1</xstream.version>
-    <commons-lang.version>3.9</commons-lang.version>
+    <dom4j.version>1.6.1</dom4j.version>
+    <commons-lang.version>3.8.1</commons-lang.version>
     <json-lib.version>2.4</json-lib.version>
     <httpclient.version>4.5.8</httpclient.version>
     <httpcore.version>4.4.11</httpcore.version>
@@ -169,7 +171,7 @@
       <dependency>
         <groupId>org.junit</groupId>
         <artifactId>junit-bom</artifactId>
-        <version>5.5.2</version>
+        <version>5.7.0</version>
         <scope>import</scope>
         <type>pom</type>
       </dependency>
@@ -209,9 +211,16 @@
         <type>pom</type>
       </dependency>
       <dependency>
-        <groupId>xerces</groupId>
-        <artifactId>xmlParserAPIs</artifactId>
-        <version>2.6.1</version>
+        <groupId>org.junit.jupiter</groupId>
+        <artifactId>junit-jupiter-api</artifactId>
+        <version>${junit.jupiter.version}</version>
+        <scope>test</scope>
+      </dependency>
+      <dependency>
+        <groupId>junit</groupId>
+        <artifactId>junit</artifactId>
+        <version>${junit.version}</version>
+        <scope>test</scope>
       </dependency>
     </dependencies>
   </dependencyManagement>
@@ -237,12 +246,14 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-source-plugin</artifactId>
-          <version>3.1.0</version>
+          <version>3.0.1</version>
           <executions>
             <!--
-              ! here we override the super-pom attach-sources execution id which
+              ! here we override the super-pom attach-sources execution id 
+              which
               ! calls sources:jar goal. That goals forks the lifecycle,
-              ! causing the generate-sources phase to be called twice for the install goal.
+              ! causing the generate-sources phase to be called twice for 
+              the install goal.
               ! With Maven 3.4.0 this will become superfluous.
             -->
             <execution>
@@ -259,17 +270,17 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-failsafe-plugin</artifactId>
-          <version>2.22.2</version>
+          <version>2.22.1</version>
         </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-surefire-report-plugin</artifactId>
-          <version>2.22.2</version>
+          <version>2.22.1</version>
         </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-shade-plugin</artifactId>
-          <version>3.2.1</version>
+          <version>2.4.3</version>
         </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
@@ -300,12 +311,12 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-deploy-plugin</artifactId>
-          <version>3.0.0-M1</version>
+          <version>2.8.2</version>
         </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-install-plugin</artifactId>
-          <version>3.0.0-M1</version>
+          <version>2.5.2</version>
         </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
@@ -338,12 +349,12 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-javadoc-plugin</artifactId>
-          <version>3.1.1</version>
+          <version>3.1.0</version>
         </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-site-plugin</artifactId>
-          <version>3.8.2</version>
+          <version>3.7.1</version>
         </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
@@ -458,7 +469,7 @@
   <repositories>
     <repository>
       <id>repo.jenkins-ci.org</id>
-      <url>https://repo.jenkins-ci.org/public/</url>
+      <url>http://repo.jenkins-ci.org/public/</url>
     </repository>
   </repositories>