diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h
index 64795f2a68c7..ab7d59d2546a 100644
--- a/sys/sys/cdefs.h
+++ b/sys/sys/cdefs.h
@@ -212,7 +212,6 @@
 #define	__unused
 #define	__packed
 #define	__aligned(x)
-#define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx)
 #define	__section(x)
 #define	__weak
 #else
@@ -237,12 +236,6 @@
 #define	__aligned(x)	__attribute__((__aligned__(x)))
 #define	__section(x)	__attribute__((__section__(x)))
 #endif
-#if __has_attribute(argument_with_type_tag)
-#define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx) \
-	    __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx)))
-#else
-#define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx)
-#endif
 #if defined(__INTEL_COMPILER)
 #define	__dead2		__attribute__((__noreturn__))
 #define	__pure2		__attribute__((__const__))
@@ -775,6 +768,24 @@
 #define	__NO_TLS 1
 #endif
 
+/*
+ * Type Safety Checking
+ *
+ * Clang provides additional attributes to enable checking type safety
+ * properties that cannot be enforced by the C type system. 
+ */
+
+#if __has_attribute(argument_with_type_tag) && \
+    __has_attribute(type_tag_for_datatype) && !defined(lint)
+#define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx) \
+	    __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx)))
+#define	__datatype_type_tag(kind, type) \
+	    __attribute__((__type_tag_for_datatype__(kind, type)))
+#else
+#define	__arg_type_tag(arg_kind, arg_idx, type_tag_idx)
+#define	__datatype_type_tag(kind, type)
+#endif
+
 /*
  * Lock annotations.
  *