@@ -55,11 +55,11 @@
 	);
 
 	return i;
 }
 
-static OF_INLINE void*
+static OF_INLINE void *_Nullable
 of_atomic_ptr_add(void *volatile _Nullable *_Nonnull p, intptr_t i)
 {
 #if defined(OF_X86_64_ASM)
 	__asm__ __volatile__ (
 	    "lock\n\t"
@@ -125,11 +125,11 @@
 	);
 
 	return i;
 }
 
-static OF_INLINE void*
+static OF_INLINE void *_Nullable
 of_atomic_ptr_sub(void *volatile _Nullable *_Nonnull p, intptr_t i)
 {
 #if defined(OF_X86_64_ASM)
 	__asm__ __volatile__ (
 	    "negq	%0\n\t"