diff --git a/Modules/arraymodule.c b/Modules/arraymodule.c
index 89ed27a..c505dad 100644
--- a/Modules/arraymodule.c
+++ b/Modules/arraymodule.c
@@ -652,6 +652,9 @@
 		PyErr_BadArgument();
 		return NULL;
 	}
+	if (Py_SIZE(a) > PY_SSIZE_T_MAX - Py_SIZE(b)) {
+		return PyErr_NoMemory();
+	}
 	size = Py_SIZE(a) + Py_SIZE(b);
 	np = (arrayobject *) newarrayobject(&Arraytype, size, a->ob_descr);
 	if (np == NULL) {
@@ -674,6 +677,9 @@
 	Py_ssize_t nbytes;
 	if (n < 0)
 		n = 0;
+	if ((Py_SIZE(a) != 0) && (n > PY_SSIZE_T_MAX / Py_SIZE(a))) {
+		return PyErr_NoMemory();
+	}
 	size = Py_SIZE(a) * n;
 	np = (arrayobject *) newarrayobject(&Arraytype, size, a->ob_descr);
 	if (np == NULL)
@@ -818,6 +824,11 @@
 			     "can only extend with array of same kind");
 		return -1;
 	}
+	if ((Py_SIZE(self) > PY_SSIZE_T_MAX - Py_SIZE(b)) ||
+		((Py_SIZE(self) + Py_SIZE(b)) > PY_SSIZE_T_MAX / self->ob_descr->itemsize)) {
+			PyErr_NoMemory();
+			return -1;
+	}
 	size = Py_SIZE(self) + Py_SIZE(b);
         PyMem_RESIZE(self->ob_item, char, size*self->ob_descr->itemsize);
         if (self->ob_item == NULL) {
@@ -859,6 +870,10 @@
 		if (n < 0)
 			n = 0;
 		items = self->ob_item;
+		if ((self->ob_descr->itemsize != 0) && 
+			(Py_SIZE(self) > PY_SSIZE_T_MAX / self->ob_descr->itemsize)) {
+			return PyErr_NoMemory();
+		}
 		size = Py_SIZE(self) * self->ob_descr->itemsize;
 		if (n == 0) {
 			PyMem_FREE(items);
@@ -867,6 +882,9 @@
 			self->allocated = 0;
 		}
 		else {
+			if (size > PY_SSIZE_T_MAX / n) {
+				return PyErr_NoMemory();
+			}
 			PyMem_Resize(items, char, n * size);
 			if (items == NULL)
 				return PyErr_NoMemory();
@@ -1148,6 +1166,10 @@
 		Py_INCREF(dict);
 	}
 	if (Py_SIZE(array) > 0) {
+		if (array->ob_descr->itemsize 
+				> PY_SSIZE_T_MAX / array->ob_size) {
+			return PyErr_NoMemory();
+		}
 		result = Py_BuildValue("O(cs#)O", 
 			Py_TYPE(array), 
 			array->ob_descr->typecode,
@@ -1330,6 +1352,9 @@
 			if ((*self->ob_descr->setitem)(self,
 					Py_SIZE(self) - n + i, v) != 0) {
 				Py_SIZE(self) -= n;
+				if (itemsize && (self->ob_size > PY_SSIZE_T_MAX / itemsize)) {
+					return PyErr_NoMemory();
+				}
 				PyMem_RESIZE(item, char,
 					          Py_SIZE(self) * itemsize);
 				self->ob_item = item;
@@ -1389,6 +1414,10 @@
 	n = n / itemsize;
 	if (n > 0) {
 		char *item = self->ob_item;
+		if ((n > PY_SSIZE_T_MAX - Py_SIZE(self)) ||
+			((Py_SIZE(self) + n) > PY_SSIZE_T_MAX / itemsize)) {
+				return PyErr_NoMemory();
+		}
 		PyMem_RESIZE(item, char, (Py_SIZE(self) + n) * itemsize);
 		if (item == NULL) {
 			PyErr_NoMemory();
@@ -1414,8 +1443,12 @@
 static PyObject *
 array_tostring(arrayobject *self, PyObject *unused)
 {
-	return PyString_FromStringAndSize(self->ob_item,
+	if (self->ob_size <= PY_SSIZE_T_MAX / self->ob_descr->itemsize) {
+		return PyString_FromStringAndSize(self->ob_item,
 				    Py_SIZE(self) * self->ob_descr->itemsize);
+	} else {
+		return PyErr_NoMemory();
+	}
 }
 
 PyDoc_STRVAR(tostring_doc,
@@ -1443,6 +1476,9 @@
 	}
 	if (n > 0) {
 		Py_UNICODE *item = (Py_UNICODE *) self->ob_item;
+		if (Py_SIZE(self) > PY_SSIZE_T_MAX - n) {
+			return PyErr_NoMemory();
+		}
 		PyMem_RESIZE(item, Py_UNICODE, Py_SIZE(self) + n);
 		if (item == NULL) {
 			PyErr_NoMemory();