diff --git a/docs/update-type-definition-guideline.rst b/docs/update-type-definition-guideline.rst
index 38d3c5a..678d331 100644
--- a/docs/update-type-definition-guideline.rst
+++ b/docs/update-type-definition-guideline.rst
@@ -619,7 +619,7 @@ but it always updates the instances to the new format, which cannot be used by a
 
 
 Java and Javascript Backwards Compatibility
-----------------------------
+-------------------------------------------
 
 This solution is Java compliant from a code perspective and the old properties are keep for old clients.