diff --git a/core/lib/Drupal/Component/DependencyInjection/composer.json b/core/lib/Drupal/Component/DependencyInjection/composer.json
index 28dc031..46607a1 100644
--- a/core/lib/Drupal/Component/DependencyInjection/composer.json
+++ b/core/lib/Drupal/Component/DependencyInjection/composer.json
@@ -12,8 +12,10 @@
   },
   "require": {
     "php": ">=5.5.9",
-    "symfony/dependency-injection": "2.7.*",
-    "symfony/expression-language": "2.7.*"
+    "symfony/dependency-injection": "2.7.*"
+  },
+  "suggest": {
+    "symfony/expression-language": "For using expressions in service container configuration"
   },
   "autoload": {
     "psr-4": {