diff -r db600c927b2b Objects/unicodeobject.c
--- a/Objects/unicodeobject.c	Sun Aug 24 12:23:36 2014 +0300
+++ b/Objects/unicodeobject.c	Sun Aug 24 13:17:11 2014 +0300
@@ -816,7 +816,7 @@
     assert(_PyUnicode_WSTR(unicode) != NULL);
 
     /* check for integer overflow */
-    if (length > PY_SSIZE_T_MAX / sizeof(wchar_t) - 1) {
+    if (length > PY_SSIZE_T_MAX / (int)sizeof(wchar_t) - 1) {
         PyErr_NoMemory();
         return -1;
     }
@@ -888,7 +888,7 @@
     }
 
     /* Ensure we won't overflow the size. */
-    if (length > ((PY_SSIZE_T_MAX / sizeof(Py_UNICODE)) - 1)) {
+    if (length > ((PY_SSIZE_T_MAX / (int)sizeof(Py_UNICODE)) - 1)) {
         return (PyUnicodeObject *)PyErr_NoMemory();
     }
     if (length < 0) {
@@ -2239,7 +2239,7 @@
     if (copy_null)
         targetlen++;
     if (!target) {
-        if (PY_SSIZE_T_MAX / sizeof(Py_UCS4) < targetlen) {
+        if (PY_SSIZE_T_MAX / (int)sizeof(Py_UCS4) < targetlen) {
             PyErr_NoMemory();
             return NULL;
         }
@@ -2852,7 +2852,7 @@
     buflen = unicode_aswidechar(unicode, NULL, 0);
     if (buflen == -1)
         return NULL;
-    if (PY_SSIZE_T_MAX / sizeof(wchar_t) < buflen) {
+    if (PY_SSIZE_T_MAX / (int)sizeof(wchar_t) < buflen) {
         PyErr_NoMemory();
         return NULL;
     }
@@ -15394,7 +15394,7 @@
     if (u == NULL)
         return NULL;
     /* Ensure we won't overflow the size. */
-    if (len > ((PY_SSIZE_T_MAX / sizeof(Py_UNICODE)) - 1)) {
+    if (len > ((PY_SSIZE_T_MAX / (int)sizeof(Py_UNICODE)) - 1)) {
         PyErr_NoMemory();
         return NULL;
     }