Index: Modules/_tkinter.c
===================================================================
--- Modules/_tkinter.c	(revision 67313)
+++ Modules/_tkinter.c	(working copy)
@@ -1903,7 +1903,7 @@
  * function or method.
  */
 static int
-PythonCmd(ClientData clientData, Tcl_Interp *interp, int argc, char *argv[])
+PythonCmd(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *const objv[])
 {
 	PythonCmd_ClientData *data = (PythonCmd_ClientData *)clientData;
 	PyObject *self, *func, *arg, *res;
@@ -1919,11 +1919,12 @@
 	func = data->func;
 
 	/* Create argument list (argv1, ..., argvN) */
-	if (!(arg = PyTuple_New(argc - 1)))
+	if (!(arg = PyTuple_New(objc - 1)))
 		return PythonCmd_Error(interp);
 
-	for (i = 0; i < (argc - 1); i++) {
-		PyObject *s = PyUnicode_FromString(argv[i + 1]);
+	for (i = 0; i < (objc - 1); i++) {
+		PyObject *s = PyUnicode_FromUnicode(Tcl_GetUnicode(objv[i + 1]),
+				     Tcl_GetCharLength(objv[i + 1]));
 		if (!s || PyTuple_SetItem(arg, i, s)) {
 			Py_DECREF(arg);
 			return PythonCmd_Error(interp);
@@ -1983,7 +1984,7 @@
 Tkapp_CommandProc(CommandEvent *ev, int flags)
 {
 	if (ev->create)
-		*ev->status = Tcl_CreateCommand(
+		*ev->status = Tcl_CreateObjCommand(
 			ev->interp, ev->name, PythonCmd,
 			ev->data, PythonCmdDelete) == NULL;
 	else
@@ -2037,7 +2038,7 @@
 	}
 	else {
 		ENTER_TCL
-		err = Tcl_CreateCommand(
+		err = Tcl_CreateObjCommand(
 			Tkapp_Interp(self), cmdName, PythonCmd,
 			(ClientData)data, PythonCmdDelete) == NULL;
 		LEAVE_TCL