diff --git a/aip/client-libraries/4223.md b/aip/client-libraries/4223.md
index df3c178027..4ae81ab236 100644
--- a/aip/client-libraries/4223.md
+++ b/aip/client-libraries/4223.md
@@ -19,7 +19,7 @@ specific request fields.
 
 Client libraries **must not** implement client-side payload validation based
 on the `google.api.field_behavior` annotation, except to prevent
-[local failures](4223.md#local-failures).
+[local failures](4223#local-failures).
 
 The reason for this is that the `google.api.field_behavior` annotation is
 primarily a machine-readable form of _documentation_, and **not** a