diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/EnvConfigurator.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/EnvConfigurator.php
index c41b281445..21d9b84df1 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/EnvConfigurator.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/EnvConfigurator.php
@@ -31,6 +31,18 @@ class EnvConfigurator
         return '%env('.implode(':', $this->stack).')%';
     }
 
+    /**
+     * @return $this
+     */
+    public function __call(string $name, array $arguments): self
+    {
+        $processor = strtolower(preg_replace(['/([A-Z]+)([A-Z][a-z])/', '/([a-z\d])([A-Z])/'], '\1_\2', $name));
+
+        $this->custom($processor, ...$arguments);
+
+        return $this;
+    }
+
     /**
      * @return $this
      */
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Loader/Configurator/EnvConfiguratorTest.php b/src/Symfony/Component/DependencyInjection/Tests/Loader/Configurator/EnvConfiguratorTest.php
index d866752798..0b354e7615 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Loader/Configurator/EnvConfiguratorTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Loader/Configurator/EnvConfiguratorTest.php
@@ -31,5 +31,6 @@ final class EnvConfiguratorTest extends TestCase
         yield ['%env(string:FOO)%', (new EnvConfigurator('FOO'))->string()];
         yield ['%env(key:path:url:FOO)%', (new EnvConfigurator('FOO'))->url()->key('path')];
         yield ['%env(default:fallback:bar:arg1:FOO)%', (new EnvConfigurator('FOO'))->custom('bar', 'arg1')->default('fallback')];
+        yield ['%env(my_processor:my_argument:FOO)%', (new EnvConfigurator('FOO'))->myProcessor('my_argument')];
     }
 }