diff --git a/src/backend/utils/adt/varchar.c b/src/backend/utils/adt/varchar.c
index b21137c583..416c73f728 100644
--- a/src/backend/utils/adt/varchar.c
+++ b/src/backend/utils/adt/varchar.c
@@ -785,6 +785,8 @@ bpcharne(PG_FUNCTION_ARGS)
 	bool		result;
 	Oid			collid = PG_GET_COLLATION();
 
+	check_collation_set(collid);
+
 	len1 = bcTruelen(arg1);
 	len2 = bcTruelen(arg2);