diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index 4cc7f645c317..6c347eccc011 100644
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -2030,6 +2030,8 @@ waitonlock_error_callback(void *arg)
 	errcontext("waiting for %s on %s",
 			   GetLockmodeName(tag->locktag_lockmethodid, mode),
 			   locktagbuf.data);
+
+	pfree(locktagbuf.data);
 }
 
 /*