diff --git a/include/mask.h b/include/mask.h
index 8b2f970a1..e9276e55b 100755
--- a/include/mask.h
+++ b/include/mask.h
@@ -496,11 +496,11 @@ public:
 
 #define FOR_EACH_MASK_FIELD(__m, __i, __f) \
         TMask_field* __f = NULL;           \
-        for (int __i = 0; __i < __m.fields() && (__f=&__m.fld(__i))!=NULL; __i++)  
+        for (int __i = 0; __i < (__m).fields() && (__f=&(__m).fld(__i))!=NULL; __i++)  
 
 #define FOR_EACH_MASK_SHEET(__m, __i, __s) \
         TSheet_field* __s = NULL;          \
-        for (int __i = 0; __i < __m.fields() && (__s=(TSheet_field*)&__m.fld(__i))!= NULL; __i++) if (__m.fld(__i).is_sheet())
+        for (int __i = 0; __i < (__m).fields() && (__s=(TSheet_field*)&(__m).fld(__i))!= NULL; __i++) if ((__m).fld(__i).is_sheet())
 
 
 #endif // __MASK_H