Index: Modules/timemodule.c
===================================================================
--- Modules/timemodule.c	(revision 55520)
+++ Modules/timemodule.c	(working copy)
@@ -603,8 +603,11 @@
 	buf = *localtime(&tt);
 	if (!gettmarg(tup, &buf))
 		return NULL;
+
+        /* invalid value that will not be changed if there is an error. */
+        buf.tm_wday = 42;
 	tt = mktime(&buf);
-	if (tt == (time_t)(-1)) {
+	if ((tt == (time_t)(-1)) && (buf.tm_wday == 42)) {
 		PyErr_SetString(PyExc_OverflowError,
 				"mktime argument out of range");
 		return NULL;