diff --git a/src/Symfony/Bundle/WebProfilerBundle/README.md b/src/Symfony/Bundle/WebProfilerBundle/README.md
index 03780d5e59..48e6075636 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/README.md
+++ b/src/Symfony/Bundle/WebProfilerBundle/README.md
@@ -1,6 +1,12 @@
 WebProfilerBundle
 =================
 
+The Web profiler bundle is a **development tool** that gives detailed
+information about the execution of any request.
+
+**Never** enable it on production servers as it will lead to major security
+vulnerabilities in your project.
+
 Resources
 ---------