diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index efc74e8f2d7..0c6e5f24ba1 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -6589,4 +6589,5 @@ invalid_pair:
 	ereport(ERROR,
 			(errcode(ERRCODE_SYNTAX_ERROR),
 			 errmsg("invalid Unicode surrogate pair")));
+	PG_RETURN_NULL();			/* keep compiler quiet */
 }