diff --git a/Python/errors.c b/Python/errors.c
index 7b71051..66a734e 100644
--- a/Python/errors.c
+++ b/Python/errors.c
@@ -551,7 +551,8 @@
 			goto failure;
 	}
 	if (PyDict_GetItemString(dict, "__module__") == NULL) {
-		modulename = PyString_FromStringAndSize(name, (int)(dot-name));
+		modulename = PyString_FromStringAndSize(name,
+						     (Py_ssize_t)(dot-name));
 		if (modulename == NULL)
 			goto failure;
 		if (PyDict_SetItemString(dict, "__module__", modulename) != 0)
diff --git a/Python/getargs.c b/Python/getargs.c
index b676a5e..a848116 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -815,7 +815,7 @@
 #endif
 			else
 				return converterr("string", arg, msgbuf, bufsize);
-			if ((int)strlen(*p) != PyString_Size(arg))
+			if ((Py_ssize_t)strlen(*p) != PyString_Size(arg))
 				return converterr("string without null bytes",
 						  arg, msgbuf, bufsize);
 		}
@@ -882,7 +882,7 @@
 				format++;
 			}
 			else if (*p != NULL &&
-				 (int)strlen(*p) != PyString_Size(arg))
+				 (Py_ssize_t)strlen(*p) != PyString_Size(arg))
 				return converterr(
 					"string without null bytes or None", 
 					arg, msgbuf, bufsize);
@@ -1029,7 +1029,8 @@
 			   PyMem_Free()ing it after usage
 
 			*/
-			if ((int)strlen(PyString_AS_STRING(s)) != size) {
+			if ((Py_ssize_t)strlen(PyString_AS_STRING(s))
+								!= size) {
 				Py_DECREF(s);
 				return converterr(
 					"(encoded string without NULL bytes)",
diff --git a/Python/marshal.c b/Python/marshal.c
index c3bc87f..776836e 100644
--- a/Python/marshal.c
+++ b/Python/marshal.c
@@ -546,6 +546,11 @@
 			int size;
 			PyLongObject *ob;
 			n = r_long(p);
+			if (n < -INT_MAX || n > INT_MAX) {
+				PyErr_SetString(PyExc_ValueError,
+						"bad marshal data");
+				return NULL;
+			}
 			size = n<0 ? -n : n;
 			ob = _PyLong_New(size);
 			if (ob == NULL)
@@ -654,7 +659,7 @@
 	case TYPE_INTERNED:
 	case TYPE_STRING:
 		n = r_long(p);
-		if (n < 0) {
+		if (n < 0 || n > INT_MAX) {
 			PyErr_SetString(PyExc_ValueError, "bad marshal data");
 			return NULL;
 		}
@@ -689,7 +694,7 @@
 		char *buffer;
 
 		n = r_long(p);
-		if (n < 0) {
+		if (n < 0 || n > INT_MAX) {
 			PyErr_SetString(PyExc_ValueError, "bad marshal data");
 			return NULL;
 		}
@@ -710,7 +715,7 @@
 
 	case TYPE_TUPLE:
 		n = r_long(p);
-		if (n < 0) {
+		if (n < 0 || n > INT_MAX) {
 			PyErr_SetString(PyExc_ValueError, "bad marshal data");
 			return NULL;
 		}
@@ -733,7 +738,7 @@
 
 	case TYPE_LIST:
 		n = r_long(p);
-		if (n < 0) {
+		if (n < 0 || n > INT_MAX) {
 			PyErr_SetString(PyExc_ValueError, "bad marshal data");
 			return NULL;
 		}
@@ -831,10 +836,11 @@
 			
 			v = NULL;
 
-			argcount = r_long(p);
-			nlocals = r_long(p);
-			stacksize = r_long(p);
-			flags = r_long(p);
+                        /* XXX ignore long->int overflows for now */
+			argcount = (int)r_long(p);
+			nlocals = (int)r_long(p);
+			stacksize = (int)r_long(p);
+			flags = (int)r_long(p);
 			code = r_object(p);
 			if (code == NULL)
 				goto code_error;
@@ -859,7 +865,7 @@
 			name = r_object(p);
 			if (name == NULL)
 				goto code_error;
-			firstlineno = r_long(p);
+			firstlineno = (int)r_long(p);
 			lnotab = r_object(p);
 			if (lnotab == NULL)
 				goto code_error;
@@ -1031,10 +1037,16 @@
 	wf.strings = (version > 0) ? PyDict_New() : NULL;
 	w_object(x, &wf);
 	Py_XDECREF(wf.strings);
-	if (wf.str != NULL)
-		_PyString_Resize(&wf.str,
-		    (int) (wf.ptr -
-			   PyString_AS_STRING((PyStringObject *)wf.str)));
+	if (wf.str != NULL) {
+		char *base = PyString_AS_STRING((PyStringObject *)wf.str);
+		if (wf.ptr - base > PY_SSIZE_T_MAX) {
+			Py_DECREF(wf.str);
+			PyErr_SetString(PyExc_OverflowError,
+					"too much marshall data for a string");
+			return NULL;
+		}
+		_PyString_Resize(&wf.str, (Py_ssize_t)(wf.ptr - base));
+	}
 	if (wf.error) {
 		Py_XDECREF(wf.str);
 		PyErr_SetString(PyExc_ValueError,
diff --git a/Python/modsupport.c b/Python/modsupport.c
index e291014..1aa3df2 100644
--- a/Python/modsupport.c
+++ b/Python/modsupport.c
@@ -421,7 +421,7 @@
 							"string too long for Python string");
 						return NULL;
 					}
-					n = (int)m;
+					n = (Py_ssize_t)m;
 				}
 				v = PyString_FromStringAndSize(str, n);
 			}
diff --git a/Python/mystrtoul.c b/Python/mystrtoul.c
index 0dda4be..f007057 100644
--- a/Python/mystrtoul.c
+++ b/Python/mystrtoul.c
@@ -195,13 +195,10 @@
 	return (unsigned long)-1;
 }
 
-/* Checking for overflow in PyOS_strtol is a PITA since C doesn't define
- * anything about what happens when a signed integer operation overflows,
- * and some compilers think they're doing you a favor by being "clever"
- * then.  Python assumes a 2's-complement representation, so that the bit
- * pattern for the largest postive signed long is LONG_MAX, and for
- * the smallest negative signed long is LONG_MAX + 1.
+/* Checking for overflow in PyOS_strtol is a PITA; see comments
+ * about PY_ABS_LONG_MIN in longobject.c.
  */
+#define PY_ABS_LONG_MIN		(0-(unsigned long)LONG_MIN)
 
 long
 PyOS_strtol(char *str, char **ptr, int base)
@@ -224,8 +221,7 @@
 		if (sign == '-')
 			result = -result;
 	}
-	else if (sign == '-' && uresult == (unsigned long)LONG_MAX + 1) {
-		assert(LONG_MIN == -LONG_MAX-1);
+	else if (sign == '-' && uresult == PY_ABS_LONG_MIN) {
 		result = LONG_MIN;
 	}
 	else {
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 2dbe283..6fbaba5 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -1225,7 +1225,7 @@
 		p = strchr(path, delim);
 		if (p == NULL)
 			p = strchr(path, '\0'); /* End of string */
-		w = PyString_FromStringAndSize(path, (int) (p - path));
+		w = PyString_FromStringAndSize(path, (Py_ssize_t) (p - path));
 		if (w == NULL) {
 			Py_DECREF(v);
 			return NULL;