diff --git a/src/Symfony/Component/Debug/composer.json b/src/Symfony/Component/Debug/composer.json
index 67eb924680..de68db4287 100644
--- a/src/Symfony/Component/Debug/composer.json
+++ b/src/Symfony/Component/Debug/composer.json
@@ -19,6 +19,9 @@
         "php": ">=5.3.3",
         "psr/log": "~1.0"
     },
+    "conflict": {
+        "symfony/http-kernel": ">=2.3,<2.3.24|~2.4.0|>=2.5,<2.5.9|>=2.6,<2.6.2"
+    },
     "require-dev": {
         "symfony/class-loader": "~2.2",
         "symfony/http-kernel": "~2.3.24|~2.5.9|~2.6,>=2.6.2",