diff --git a/Misc/NEWS b/Misc/NEWS
index ab86a14d934..28c6c2a96a7 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -141,6 +141,8 @@ Extension Modules
 
 - Build using system ffi library on arm*-linux*.
 
+- Bug #1372: zlibmodule.c: int overflow in PyZlib_decompress
+
 
 Documentation
 -------------
diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c
index da31e8b2827..8cadcbc52cb 100644
--- a/Modules/zlibmodule.c
+++ b/Modules/zlibmodule.c
@@ -197,10 +197,11 @@ PyZlib_decompress(PyObject *self, PyObject *args)
     PyObject *result_str;
     Byte *input;
     int length, err;
-    int wsize=DEF_WBITS, r_strlen=DEFAULTALLOC;
+    int wsize=DEF_WBITS;
+    Py_ssize_t r_strlen=DEFAULTALLOC;
     z_stream zst;
 
-    if (!PyArg_ParseTuple(args, "s#|ii:decompress",
+    if (!PyArg_ParseTuple(args, "s#|in:decompress",
 			  &input, &length, &wsize, &r_strlen))
 	return NULL;