diff --git a/python-crypto-2.6.1-python3.11.patch b/python-crypto-2.6.1-python3.11.patch
new file mode 100644
index 0000000..c52b1f7
--- /dev/null
+++ b/python-crypto-2.6.1-python3.11.patch
@@ -0,0 +1,10 @@
+--- src/_fastmath.c
++++ src/_fastmath.c
+@@ -30,7 +30,6 @@
+ #include <string.h>
+ #include "Python.h"
+ #include "pycrypto_compat.h"
+-#include <longintrepr.h>				/* for conversions */
+ #include "config.h"
+ #if HAVE_LIBGMP
+ # include <gmp.h>
diff --git a/python-crypto.spec b/python-crypto.spec
index 4d8b0a6..eeea671 100644
--- a/python-crypto.spec
+++ b/python-crypto.spec
@@ -7,7 +7,7 @@
 Summary:	Cryptography library for Python
 Name:		python-crypto
 Version:	2.6.1
-Release:	36%{?dist}
+Release:	37%{?dist}
 # Mostly Public Domain apart from parts of HMAC.py and setup.py, which are Python
 License:	Public Domain and Python
 URL:		http://www.pycrypto.org/
@@ -21,6 +21,7 @@ Patch5:		pycrypto-2.6.1-CVE-2018-6594.patch
 Patch6:		pycrypto-2.6.1-use-os-random.patch
 Patch7:		pycrypto-2.6.1-drop-py2.1-support.patch
 Patch8:		python-crypto-2.6.1-python3.10.patch
+Patch9:		python-crypto-2.6.1-python3.11.patch
 BuildRequires:	coreutils
 BuildRequires:	findutils
 BuildRequires:	gcc
@@ -89,6 +90,10 @@ rm -rf src/libtom
 # https://bugzilla.redhat.com/show_bug.cgi?id=1897544
 %patch8
 
+# Fix Python 3.11 compatibility
+# https://bugzilla.redhat.com/show_bug.cgi?id=2021808
+%patch9
+
 # setup.py doesn't run 2to3 on pct-speedtest.py
 cp pct-speedtest.py pct-speedtest3.py
 2to3 -wn pct-speedtest3.py
@@ -116,6 +121,9 @@ PYTHONPATH=%{buildroot}%{python3_sitearch} %{__python3} pct-speedtest3.py
 %{python3_sitearch}/pycrypto-%{version}-py3.*.egg-info
 
 %changelog
+* Wed Nov 10 2021 Paul Howarth <paul@city-fan.org> - 2.6.1-37
+- Fix Python 3.11 compatibility (#2021808)
+
 * Fri Jul 23 2021 Fedora Release Engineering <releng@fedoraproject.org> - 2.6.1-36
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_35_Mass_Rebuild