diff --git a/src/Symfony/Component/DependencyInjection/CHANGELOG.md b/src/Symfony/Component/DependencyInjection/CHANGELOG.md
index c9477b8848..461d52abd1 100644
--- a/src/Symfony/Component/DependencyInjection/CHANGELOG.md
+++ b/src/Symfony/Component/DependencyInjection/CHANGELOG.md
@@ -14,6 +14,7 @@ CHANGELOG
  * added ability to define a static priority method for tagged service
  * added support for improved syntax to define method calls in Yaml
  * added `LazyString` for lazy computation of string values injected into services
+ * made the `%env(base64:...)%` processor able to decode base64url
 
 4.3.0
 -----
diff --git a/src/Symfony/Component/DependencyInjection/EnvVarProcessor.php b/src/Symfony/Component/DependencyInjection/EnvVarProcessor.php
index 9231cf48c5..aef13a9ad1 100644
--- a/src/Symfony/Component/DependencyInjection/EnvVarProcessor.php
+++ b/src/Symfony/Component/DependencyInjection/EnvVarProcessor.php
@@ -173,7 +173,7 @@ class EnvVarProcessor implements EnvVarProcessorInterface
         }
 
         if ('base64' === $prefix) {
-            return base64_decode($env);
+            return base64_decode(strtr($env, '-_', '+/'));
         }
 
         if ('json' === $prefix) {
diff --git a/src/Symfony/Component/DependencyInjection/Tests/EnvVarProcessorTest.php b/src/Symfony/Component/DependencyInjection/Tests/EnvVarProcessorTest.php
index c960c2f1ad..12d852f453 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/EnvVarProcessorTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/EnvVarProcessorTest.php
@@ -231,6 +231,12 @@ class EnvVarProcessorTest extends TestCase
         });
 
         $this->assertSame('hello', $result);
+
+        $result = $processor->getEnv('base64', 'foo', function ($name) { return '/+0='; });
+        $this->assertSame("\xFF\xED", $result);
+
+        $result = $processor->getEnv('base64', 'foo', function ($name) { return '_-0='; });
+        $this->assertSame("\xFF\xED", $result);
     }
 
     public function testGetEnvTrim()