diff --git a/python-pyOpenSSL-always-overflow.patch b/python-pyOpenSSL-always-overflow.patch
new file mode 100644
index 0000000..ff36195
--- /dev/null
+++ b/python-pyOpenSSL-always-overflow.patch
@@ -0,0 +1,30 @@
+From b3460c6a9a45a016d1ab65c149c606fa3f07096d Mon Sep 17 00:00:00 2001
+From: Alex Gaynor <alex.gaynor@gmail.com>
+Date: Thu, 6 Jul 2017 22:40:40 -0400
+Subject: [PATCH] Fixed #657 -- handle OverflowErrors on large allocation
+ requests (#659)
+
+* Fixed #657 -- handle OverflowErrors on large allocation requests
+
+* always be overflowing
+
+diff --git a/tests/test_rand.py b/tests/test_rand.py
+index bdd3af0..41a4f27 100644
+--- a/tests/test_rand.py
++++ b/tests/test_rand.py
+@@ -32,11 +32,11 @@ class TestRand(object):
+ 
+     def test_insufficient_memory(self):
+         """
+-        `OpenSSL.rand.bytes` raises `MemoryError` if more bytes are requested
+-        than will fit in memory.
++        `OpenSSL.rand.bytes` raises `MemoryError` or `OverflowError` if more
++        bytes are requested than will fit in memory.
+         """
+-        with pytest.raises(MemoryError):
+-            rand.bytes(sys.maxsize)
++        with pytest.raises((MemoryError, OverflowError)):
++            rand.bytes(sys.maxsize + 1)
+ 
+     def test_bytes(self):
+         """
diff --git a/python-pyOpenSSL.changes b/python-pyOpenSSL.changes
index 416357f..f87c40c 100644
--- a/python-pyOpenSSL.changes
+++ b/python-pyOpenSSL.changes
@@ -1,3 +1,11 @@
+-------------------------------------------------------------------
+Thu Aug 10 11:38:17 CEST 2017 - ro@suse.de
+
+- add patch to always trigger overflow in the testsuite
+  (gh#pyca/pyopenssl#657) b3460c6a9a45a016d1ab65c149c606fa3f07096d
+ 
+  python-pyOpenSSL-always-overflow.patch 
+
 -------------------------------------------------------------------
 Tue Jun 13 07:05:41 UTC 2017 - dimstar@opensuse.org
 
diff --git a/python-pyOpenSSL.spec b/python-pyOpenSSL.spec
index 206ec47..bd091da 100644
--- a/python-pyOpenSSL.spec
+++ b/python-pyOpenSSL.spec
@@ -33,6 +33,8 @@ Patch1:         skip-networked-test.patch
 Patch2:         rsa128-i586.patch
 # PATCH-FIX-UPSTREAM python-pyOpenSSL=replace-expired-cert.patch gh#pyca/pyopenssl#637 dimstar@opensuse.org -- the root cert expired
 Patch3:         python-pyOpenSSL=replace-expired-cert.patch
+# PATCH-FIX-UPSTREAM python-pyOpenSSL-always-overflow.patch gh#pyca/pyopenssl#657 ro@suse.de - always trigger overflow in testsuite
+Patch4:         python-pyOpenSSL-always-overflow.patch
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
 BuildRequires:  %{python_module cryptography >= 1.3.4}
 BuildRequires:  %{python_module devel}
@@ -75,6 +77,7 @@ Provides documentation for %{name}.
 %patch1 -p1
 %patch2 -p1
 %patch3 -p1
+%patch4 -p1
 
 %build
 %python_build