diff --git a/src/Symfony/Component/Debug/FatalErrorHandler/ClassNotFoundFatalErrorHandler.php b/src/Symfony/Component/Debug/FatalErrorHandler/ClassNotFoundFatalErrorHandler.php
index 2b37ee9994222..0ba0bd4483080 100644
--- a/src/Symfony/Component/Debug/FatalErrorHandler/ClassNotFoundFatalErrorHandler.php
+++ b/src/Symfony/Component/Debug/FatalErrorHandler/ClassNotFoundFatalErrorHandler.php
@@ -119,7 +119,7 @@ private function getClassCandidates($class)
             }
         }
 
-        return $classes;
+        return array_unique($classes);
     }
 
     /**