diff --git a/HISTORY b/HISTORY
index b876423..4ca97af 100755
--- a/HISTORY
+++ b/HISTORY
@@ -1,6 +1,7 @@
 Dec. 11 2015
 Added an IS statement to detect type equality of a value
 Added support to store a routine in a variable by CALL statement
+Added GC accessing to fields of a class instance
 Fixed a memory leak with GC caused by reference cycle
 Finished internal class development
 
diff --git a/core/my_basic.c b/core/my_basic.c
index 8cdf258..04f805a 100755
--- a/core/my_basic.c
+++ b/core/my_basic.c
@@ -1118,6 +1118,7 @@ static char* _extract_string(_object_t* obj);
 #else /* MB_ENABLE_COLLECTION_LIB */
 #	define _REF_COLL(__o) ((void)(__o));
 #	define _UNREF_COLL(__o) ((void)(__o));
+#	define _ADDGC_COLL(__o, __g) ((void)(__o)); ((void)(__g));
 #endif /* MB_ENABLE_COLLECTION_LIB */
 #ifdef MB_ENABLE_CLASS
 #	define _REF_CLASS(__o) \