diff --git a/tests/usr.bin/xlint/lint1/gcc_cast_union.c b/tests/usr.bin/xlint/lint1/gcc_cast_union.c
index 2ad0fc6c1f36..4fe301f7a1a9 100644
--- a/tests/usr.bin/xlint/lint1/gcc_cast_union.c
+++ b/tests/usr.bin/xlint/lint1/gcc_cast_union.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: gcc_cast_union.c,v 1.1 2021/08/03 20:34:23 rillig Exp $	*/
+/*	$NetBSD: gcc_cast_union.c,v 1.2 2021/08/03 21:09:26 rillig Exp $	*/
 # 3 "gcc_cast_union.c"
 
 /*
@@ -11,6 +11,8 @@
  * https://gcc.gnu.org/onlinedocs/gcc/Cast-to-Union.html
  */
 
+/* lint1-extra-flags: -e */
+
 union anything {
 	_Bool m_bool;
 	char m_char;
@@ -79,9 +81,9 @@ test(void)
 	any = (union anything)E1;
 	any = (union anything)E2;
 	/* GCC allows enum mismatch even with -Wenum-conversion */
-	/* expect+1: error: type 'enum other_enum' is not a member of 'union anything' [329] */
+	/* XXX: Lint should warn about enum type mismatch */
 	any = (union anything)OTHER;
-	/* GCC strictly complains that 'char *' is not in the union. */
+	/* expect+1: error: type 'pointer to char' is not a member of 'union anything' [329] */
 	any = (union anything)"char *";
 	any = (union anything)(const char *)"char *";
 	/* expect+1: error: type 'pointer to double' is not a member of 'union anything' [329] */
diff --git a/tests/usr.bin/xlint/lint1/gcc_cast_union.exp b/tests/usr.bin/xlint/lint1/gcc_cast_union.exp
index c26149ffb9ad..34addb9d1cfa 100644
--- a/tests/usr.bin/xlint/lint1/gcc_cast_union.exp
+++ b/tests/usr.bin/xlint/lint1/gcc_cast_union.exp
@@ -1,4 +1,4 @@
-gcc_cast_union.c(83): error: type 'enum other_enum' is not a member of 'union anything' [329]
-gcc_cast_union.c(88): error: type 'pointer to double' is not a member of 'union anything' [329]
+gcc_cast_union.c(87): error: type 'pointer to char' is not a member of 'union anything' [329]
 gcc_cast_union.c(90): error: type 'pointer to double' is not a member of 'union anything' [329]
-gcc_cast_union.c(92): error: type 'pointer to int' is not a member of 'union anything' [329]
+gcc_cast_union.c(92): error: type 'pointer to double' is not a member of 'union anything' [329]
+gcc_cast_union.c(94): error: type 'pointer to int' is not a member of 'union anything' [329]
diff --git a/usr.bin/xlint/lint1/tree.c b/usr.bin/xlint/lint1/tree.c
index 016eaed3ca77..f01c9a22f9d6 100644
--- a/usr.bin/xlint/lint1/tree.c
+++ b/usr.bin/xlint/lint1/tree.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: tree.c,v 1.329 2021/08/03 20:57:06 rillig Exp $	*/
+/*	$NetBSD: tree.c,v 1.330 2021/08/03 21:09:26 rillig Exp $	*/
 
 /*
  * Copyright (c) 1994, 1995 Jochen Pohl
@@ -37,7 +37,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: tree.c,v 1.329 2021/08/03 20:57:06 rillig Exp $");
+__RCSID("$NetBSD: tree.c,v 1.330 2021/08/03 21:09:26 rillig Exp $");
 #endif
 
 #include <float.h>
@@ -102,36 +102,6 @@ op_name(op_t op)
 	return modtab[op].m_name;
 }
 
-static bool
-sametype(const type_t *t1, const type_t *t2)
-{
-
-	/* Maybe this can be merged into 'eqtype'. */
-
-	if (t1->t_tspec != t2->t_tspec)
-		return false;
-
-	/* Ignore const/volatile */
-
-	switch (t1->t_tspec) {
-	case ARRAY:
-		if (t1->t_dim != t2->t_dim)
-			return false;
-		/*FALLTHROUGH*/
-	case PTR:
-		return sametype(t1->t_subt, t2->t_subt);
-	case ENUM:
-		return strcmp(t1->t_enum->en_tag->s_name,
-		    t2->t_enum->en_tag->s_name) == 0;
-	case STRUCT:
-	case UNION:
-		return strcmp(t1->t_str->sou_tag->s_name,
-		    t2->t_str->sou_tag->s_name) == 0;
-	default:
-		return true;
-	}
-}
-
 /* Build 'pointer to tp', 'array of tp' or 'function returning tp'. */
 type_t *
 derive_type(type_t *tp, tspec_t t)
@@ -3401,7 +3371,8 @@ cast(tnode_t *tn, type_t *tp)
 			return NULL;
 		}
 		for (m = str->sou_first_member; m != NULL; m = m->s_next) {
-			if (sametype(m->s_type, tn->tn_type)) {
+			if (eqtype(m->s_type, tn->tn_type,
+			    false, false, NULL)) {
 				tn = expr_zalloc_tnode();
 				tn->tn_op = CVT;
 				tn->tn_type = tp;