Index: generic/nsf.c
===================================================================
diff -u -rb9e39fb7a7a01c2b07a112700d42060eadde4d8d -r6110e3a41d85384b97604012281b73e51781290e
--- generic/nsf.c	(.../nsf.c)	(revision b9e39fb7a7a01c2b07a112700d42060eadde4d8d)
+++ generic/nsf.c	(.../nsf.c)	(revision 6110e3a41d85384b97604012281b73e51781290e)
@@ -12704,18 +12704,19 @@
   AliasCmdClientData *tcd = (AliasCmdClientData *)clientData;
   NsfObject *self = GetSelfObj(interp);
   CONST char *methodName = ObjStr(objv[0]);
+
   if (!self) {
     return NsfPrintError(interp, "Cannot resolve 'self', "
 			 "probably called outside the context of a Next Scripting Object");
   }
 
-  assert(tcd->object == self);
-
-  if (self == NULL) {
+  if (!tcd->object) {
     return NsfDispatchClientDataError(interp, tcd->object, "object", 
 				      Tcl_GetCommandName(interp, tcd->aliasCmd));
   }
 
+  assert(tcd->object == self);
+
   if (Tcl_Command_cmdEpoch(tcd->aliasedCmd)) {
     NsfObject *defObject = tcd->class ? &(tcd->class->object) : tcd->object;
     Tcl_Obj **listElements, *entryObj, *targetObj;