diff -r 6e541ed4e987 Objects/unicodeobject.c
--- a/Objects/unicodeobject.c	Mon Apr 30 19:11:11 2012 +0300
+++ b/Objects/unicodeobject.c	Mon Apr 30 20:42:31 2012 +0300
@@ -13799,7 +13799,7 @@
                     c = PyUnicode_READ(fmtkind, fmt, fmtpos++);
                     if (c < '0' || c > '9')
                         break;
-                    if ((width*10) / 10 != width) {
+                    if (width >= PY_SSIZE_T_MAX / 10) {
                         PyErr_SetString(PyExc_ValueError,
                                         "width too big");
                         goto onError;
@@ -13834,7 +13834,7 @@
                         c = PyUnicode_READ(fmtkind, fmt, fmtpos++);
                         if (c < '0' || c > '9')
                             break;
-                        if ((prec*10) / 10 != prec) {
+                        if (prec >= INT_MAX / 10) {
                             PyErr_SetString(PyExc_ValueError,
                                             "prec too big");
                             goto onError;