diff --git a/CRM/Dedupe/Merger.php b/CRM/Dedupe/Merger.php
index 78bc767444c3..413d7e5fa802 100644
--- a/CRM/Dedupe/Merger.php
+++ b/CRM/Dedupe/Merger.php
@@ -233,9 +233,6 @@ public static function cidRefs() {
     }
 
     CRM_Utils_Hook::merge('cidRefs', $contactReferences);
-    if ($contactReferences !== $coreReferences) {
-      CRM_Core_Error::deprecatedWarning("Deprecated hook ::merge in context of 'cidRefs. Use entityTypes instead.");
-    }
     \Civi::$statics[__CLASS__]['contact_references'] = $contactReferences;
     return \Civi::$statics[__CLASS__]['contact_references'];
   }