diff --git a/bip-???-cat.mediawiki b/bip-???-cat.mediawiki
index ec4834a2..6a5c54a0 100644
--- a/bip-???-cat.mediawiki
+++ b/bip-???-cat.mediawiki
@@ -41,7 +41,7 @@ For example, a script that pushed a 1-byte value on the stack and then repeated
 
 OP_CAT pops two elements off the stack, concatenates them together in stack order and pushes the resulting element onto the stack. Given the stack [x1,x2], where x2 is at the top of the stack, OP_CAT will push x1||x2 onto the stack. By '||' we denote concatenation.
 
-Implementation
+===Implementation===
 <pre>
 case OP_CAT:
 {