diff -r 20f0c5398e97 Python/marshal.c
--- a/Python/marshal.c	Mon Feb 04 10:29:38 2013 -0500
+++ b/Python/marshal.c	Wed Feb 06 17:51:35 2013 +0200
@@ -126,6 +126,21 @@
 }
 #endif
 
+#define SIZE32_MAX  0x7FFFFFFF
+
+#if SIZEOF_SIZE_T > 4
+# define W_SIZE(n, p)  do {                     \
+        if ((n) > SIZE32_MAX) {                 \
+            (p)->depth--;                       \
+            (p)->error = WFERR_UNMARSHALLABLE;  \
+            return;                             \
+        }                                       \
+        w_long((long)(n), p);                   \
+    } while(0)
+#else
+# define W_SIZE  w_long
+#endif
+
 /* We assume that Python longs are stored internally in base some power of
    2**15; for the sake of portability we'll always read and write them in base
    exactly 2**15. */
@@ -159,6 +174,11 @@
         d >>= PyLong_MARSHAL_SHIFT;
         l++;
     } while (d != 0);
+    if (l > SIZE32_MAX) {
+        p->depth--;
+        p->error = WFERR_UNMARSHALLABLE;
+        return;
+    }
     w_long((long)(Py_SIZE(ob) > 0 ? l : -l), p);
 
     for (i=0; i < n-1; i++) {
@@ -319,13 +339,7 @@
             w_byte(TYPE_STRING, p);
         }
         n = PyString_GET_SIZE(v);
-        if (n > INT_MAX) {
-            /* huge strings are not supported */
-            p->depth--;
-            p->error = WFERR_UNMARSHALLABLE;
-            return;
-        }
-        w_long((long)n, p);
+        W_SIZE(n, p);
         w_string(PyString_AS_STRING(v), (int)n, p);
     }
 #ifdef Py_USING_UNICODE
@@ -339,12 +353,7 @@
         }
         w_byte(TYPE_UNICODE, p);
         n = PyString_GET_SIZE(utf8);
-        if (n > INT_MAX) {
-            p->depth--;
-            p->error = WFERR_UNMARSHALLABLE;
-            return;
-        }
-        w_long((long)n, p);
+        W_SIZE(n, p);
         w_string(PyString_AS_STRING(utf8), (int)n, p);
         Py_DECREF(utf8);
     }
@@ -352,7 +361,7 @@
     else if (PyTuple_CheckExact(v)) {
         w_byte(TYPE_TUPLE, p);
         n = PyTuple_Size(v);
-        w_long((long)n, p);
+        W_SIZE(n, p);
         for (i = 0; i < n; i++) {
             w_object(PyTuple_GET_ITEM(v, i), p);
         }
@@ -360,7 +369,7 @@
     else if (PyList_CheckExact(v)) {
         w_byte(TYPE_LIST, p);
         n = PyList_GET_SIZE(v);
-        w_long((long)n, p);
+        W_SIZE(n, p);
         for (i = 0; i < n; i++) {
             w_object(PyList_GET_ITEM(v, i), p);
         }
@@ -390,7 +399,7 @@
             p->error = WFERR_UNMARSHALLABLE;
             return;
         }
-        w_long((long)n, p);
+        W_SIZE(n, p);
         it = PyObject_GetIter(v);
         if (it == NULL) {
             p->depth--;
@@ -432,12 +441,7 @@
         PyBufferProcs *pb = v->ob_type->tp_as_buffer;
         w_byte(TYPE_STRING, p);
         n = (*pb->bf_getreadbuffer)(v, 0, (void **)&s);
-        if (n > INT_MAX) {
-            p->depth--;
-            p->error = WFERR_UNMARSHALLABLE;
-            return;
-        }
-        w_long((long)n, p);
+        W_SIZE(n, p);
         w_string(s, (int)n, p);
     }
     else {
@@ -570,7 +574,7 @@
     n = r_long(p);
     if (n == 0)
         return (PyObject *)_PyLong_New(0);
-    if (n < -INT_MAX || n > INT_MAX) {
+    if (n < -SIZE32_MAX || n > SIZE32_MAX) {
         PyErr_SetString(PyExc_ValueError,
                        "bad marshal data (long size out of range)");
         return NULL;
@@ -795,7 +799,7 @@
     case TYPE_INTERNED:
     case TYPE_STRING:
         n = r_long(p);
-        if (n < 0 || n > INT_MAX) {
+        if (n < 0 || n > SIZE32_MAX) {
             PyErr_SetString(PyExc_ValueError, "bad marshal data (string size out of range)");
             retval = NULL;
             break;
@@ -840,7 +844,7 @@
         char *buffer;
 
         n = r_long(p);
-        if (n < 0 || n > INT_MAX) {
+        if (n < 0 || n > SIZE32_MAX) {
             PyErr_SetString(PyExc_ValueError, "bad marshal data (unicode size out of range)");
             retval = NULL;
             break;
@@ -866,7 +870,7 @@
 
     case TYPE_TUPLE:
         n = r_long(p);
-        if (n < 0 || n > INT_MAX) {
+        if (n < 0 || n > SIZE32_MAX) {
             PyErr_SetString(PyExc_ValueError, "bad marshal data (tuple size out of range)");
             retval = NULL;
             break;
@@ -893,7 +897,7 @@
 
     case TYPE_LIST:
         n = r_long(p);
-        if (n < 0 || n > INT_MAX) {
+        if (n < 0 || n > SIZE32_MAX) {
             PyErr_SetString(PyExc_ValueError, "bad marshal data (list size out of range)");
             retval = NULL;
             break;
@@ -945,7 +949,7 @@
     case TYPE_SET:
     case TYPE_FROZENSET:
         n = r_long(p);
-        if (n < 0 || n > INT_MAX) {
+        if (n < 0 || n > SIZE32_MAX) {
             PyErr_SetString(PyExc_ValueError, "bad marshal data (set size out of range)");
             retval = NULL;
             break;