diff --git a/include/defmask.h b/include/defmask.h
index 07b184f1f..17dc6d060 100755
--- a/include/defmask.h
+++ b/include/defmask.h
@@ -106,5 +106,6 @@
 #define NUM_CALC VALIDATE NUMCALC_FUNC 1
 #define STR_CALC VALIDATE STRCALC_FUNC 1
 #define THIS_FIELD 0
+#define THIS 0
 /* @END */
 #endif // __DEFMASK_H