diff --git a/include/krb5-types.cross b/include/krb5-types.cross
index 6f67443ba..ee43abd4a 100644
--- a/include/krb5-types.cross
+++ b/include/krb5-types.cross
@@ -13,8 +13,17 @@ typedef socklen_t krb5_socklen_t;
 #include <unistd.h>
 typedef ssize_t krb5_ssize_t;
 
+#if !defined(__has_extension)
+#define __has_extension(x) 0
+#endif
+
+#define KRB5TYPES_REQUIRE_GNUC(m,n,p) \
+    (((__GNUC__ * 10000) + (__GNUC_MINOR__ * 100) + __GNUC_PATCHLEVEL__) >= \
+     (((m) * 10000) + ((n) * 100) + (p)))
+
+
 #ifndef HEIMDAL_DEPRECATED
-#if defined(__GNUC__) && ((__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 1 )))
+#if __has_extension(deprecated) || KRB5TYPES_REQUIRE_GNUC(3,1,0)
 #define HEIMDAL_DEPRECATED __attribute__((deprecated))
 #elif defined(_MSC_VER) && (_MSC_VER>1200) 
 #define HEIMDAL_DEPRECATED __declspec(deprecated)
@@ -24,7 +33,7 @@ typedef ssize_t krb5_ssize_t;
 #endif
 
 #ifndef HEIMDAL_PRINTF_ATTRIBUTE
-#if defined(__GNUC__) && ((__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 1 )))
+#if __has_extension(format) || KRB5TYPES_REQUIRE_GNUC(3,1,0)
 #define HEIMDAL_PRINTF_ATTRIBUTE(x) __attribute__((format x))
 #else
 #define HEIMDAL_PRINTF_ATTRIBUTE(x)
@@ -32,7 +41,7 @@ typedef ssize_t krb5_ssize_t;
 #endif
 
 #ifndef HEIMDAL_NORETURN_ATTRIBUTE
-#if defined(__GNUC__) && ((__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 1 )))
+#if __has_extension(noreturn) || KRB5TYPES_REQUIRE_GNUC(3,1,0)
 #define HEIMDAL_NORETURN_ATTRIBUTE __attribute__((noreturn))
 #else
 #define HEIMDAL_NORETURN_ATTRIBUTE
@@ -40,7 +49,7 @@ typedef ssize_t krb5_ssize_t;
 #endif
 
 #ifndef HEIMDAL_UNUSED_ATTRIBUTE
-#if defined(__GNUC__) && ((__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 1 )))
+#if __has_extension(unused) || KRB5TYPES_REQUIRE_GNUC(3,1,0)
 #define HEIMDAL_UNUSED_ATTRIBUTE __attribute__((unused))
 #else
 #define HEIMDAL_UNUSED_ATTRIBUTE