diff --git a/sys/sys/stdatomic.h b/sys/sys/stdatomic.h
index cac36fa6adf..c2faf646e36 100644
--- a/sys/sys/stdatomic.h
+++ b/sys/sys/stdatomic.h
@@ -171,7 +171,10 @@ atomic_signal_fence(memory_order __order __unused)
 /* Atomics in kernelspace are always lock-free. */
 #define	atomic_is_lock_free(obj) \
 	((void)(obj), (_Bool)1)
-#elif defined(__CLANG_ATOMICS) || defined(__GNUC_ATOMICS)
+#elif defined(__CLANG_ATOMICS)
+#define	atomic_is_lock_free(obj) \
+	__c11_atomic_is_lock_free(sizeof(*(obj)))
+#elif defined(__GNUC_ATOMICS)
 #define	atomic_is_lock_free(obj) \
 	__atomic_is_lock_free(sizeof(*(obj)), obj)
 #else