comparison with sign

diff --git a/libasn1parser/asn1p_expr_str.h b/libasn1parser/asn1p_expr_str.h
index 7d98a55..93567f8 100644
--- a/libasn1parser/asn1p_expr_str.h
+++ b/libasn1parser/asn1p_expr_str.h
@@ -47,8 +47,8 @@
  */
 #define	ASN_EXPR_TYPE2STR(type)					\
 	(							\
-	(((ssize_t)type) < 0					\
-	|| ((size_t)type) >= sizeof(asn1p_expr_type2str)	\
+	(((ssize_t)(type)) < 0					\
+	|| ((size_t)(type)) >= sizeof(asn1p_expr_type2str)	\
 		/ sizeof(asn1p_expr_type2str[0]))		\
 		? (char *)0					\
 		: asn1p_expr_type2str[(type)]			\