diff --git a/list.h b/list.h
index d122369f13b..33b038ce8da 100644
--- a/list.h
+++ b/list.h
@@ -183,7 +183,7 @@ private:
 };
 
 #define foreach_iter(iter_type, iter, container) \
-   for (iter_type iter = container . iterator(); iter.has_next(); iter.next())
+   for (iter_type iter = (container) . iterator(); iter.has_next(); iter.next())
 #endif