diff --git a/guides/source/active_support_instrumentation.md b/guides/source/active_support_instrumentation.md
index 5c3f4dce2d33a..cb0d13f959a20 100644
--- a/guides/source/active_support_instrumentation.md
+++ b/guides/source/active_support_instrumentation.md
@@ -26,8 +26,8 @@ Rails framework hooks
 
 Within the Ruby on Rails framework, there are a number of hooks provided for common events. These are detailed below.
 
-ActionController
-----------------
+Action Controller
+-----------------
 
 ### write_fragment.action_controller