diff --git a/src/hb-atomic-private.hh b/src/hb-atomic-private.hh
index 03d7df117..684e856f7 100644
--- a/src/hb-atomic-private.hh
+++ b/src/hb-atomic-private.hh
@@ -79,7 +79,7 @@ typedef volatile int hb_atomic_int_t;
 #define HB_ATOMIC_INT_NIL 1
 typedef volatile int hb_atomic_int_t;
 #define hb_atomic_int_add(AI, V)	((AI) += (V), (AI) - (V))
-#define hb_atomic_int_set(AI)		((void) ((AI) = (V)))
+#define hb_atomic_int_set(AI, V)	((void) ((AI) = (V)))
 #define hb_atomic_int_get(AI)		(AI)
 
 #endif