proper types

diff --git a/tests/19-param-OK.asn1.-P b/tests/19-param-OK.asn1.-P
index a9f48e7..d52ab07 100644
--- a/tests/19-param-OK.asn1.-P
+++ b/tests/19-param-OK.asn1.-P
@@ -240,7 +240,7 @@
 static int check_permitted_alphabet_1(const void *sptr) {
 	int *table = permitted_alphabet_table_1;
 	/* The underlying type is IA5String */
-	const (null)_t *st = sptr;
+	const IA5String_t *st = sptr;
 	uint8_t *ch = st->buf;
 	uint8_t *end = ch + st->size;