diff --git a/src/Symfony/Component/DependencyInjection/ParameterBag/ParameterBagInterface.php b/src/Symfony/Component/DependencyInjection/ParameterBag/ParameterBagInterface.php
index 852b99b30d..041c74dd56 100644
--- a/src/Symfony/Component/DependencyInjection/ParameterBag/ParameterBagInterface.php
+++ b/src/Symfony/Component/DependencyInjection/ParameterBag/ParameterBagInterface.php
@@ -66,4 +66,18 @@ interface ParameterBagInterface
      * @return Boolean true if the parameter name is defined, false otherwise
      */
     function has($name);
+
+    /**
+     * Replaces parameter placeholders (%name%) by their values for all parameters.
+     */
+    public function resolve();
+
+    /**
+     * Replaces parameter placeholders (%name%) by their values.
+     *
+     * @param  mixed $value A value
+     *
+     * @throws NonExistentParameterException if a placeholder references a parameter that does not exist
+     */
+    public function resolveValue($value);
 }