diff --git a/src/atomic.h b/src/atomic.h
index ce414999..9207ad09 100644
--- a/src/atomic.h
+++ b/src/atomic.h
@@ -49,6 +49,14 @@ atomic_add (volatile int *ptr, int incr)
   
   return res;
 }
-#endif 
+#else
+
+static inline int 
+atomic_add(volatile int *ptr, int incr)
+{
+  return __sync_fetch_and_add(ptr, incr);
+}
+
+#endif
 
 #endif /* HTSATOMIC_H__ */