@@ -25,11 +25,11 @@
     var = objv[idx];				\
     OPT_POSTLOG()
 
 #define OPTSTR(option, var)			\
     OPT_PROLOG(option)				\
-    var = Tcl_GetStringFromObj(objv[idx], NULL);\
+    var = Tcl_GetStringFromObj(objv[idx], (Tcl_Size *)NULL);\
     OPT_POSTLOG()
 
 #define OPTINT(option, var)			\
     OPT_PROLOG(option)				\
     if (Tcl_GetIntFromObj(interp, objv[idx],	\