diff --git a/pkgs/development/python-modules/h2/default.nix b/pkgs/development/python-modules/h2/default.nix
index ba681658e9a2..d52c84d03e00 100644
--- a/pkgs/development/python-modules/h2/default.nix
+++ b/pkgs/development/python-modules/h2/default.nix
@@ -1,4 +1,4 @@
-{ lib, buildPythonPackage, fetchPypi
+{ lib, buildPythonPackage, fetchPypi, fetchpatch
 , enum34, hpack, hyperframe, pytestCheckHook, hypothesis }:
 
 buildPythonPackage rec {
@@ -10,6 +10,15 @@ buildPythonPackage rec {
     sha256 = "bb7ac7099dd67a857ed52c815a6192b6b1f5ba6b516237fc24a085341340593d";
   };
 
+  patches = [
+    # Workaround issues with hypothesis 6.6
+    # https://github.com/python-hyper/h2/pull/1248
+    (fetchpatch {
+      url = "https://github.com/python-hyper/h2/commit/0646279dab694a89562846c810202ce2c0b49be3.patch";
+      sha256 = "1k0fsxwq9wbv15sc9ixls4qmxxghlzpflf3awm66ar9m2ikahiak";
+    })
+  ];
+
   propagatedBuildInputs = [ enum34 hpack hyperframe ];
 
   checkInputs = [ pytestCheckHook hypothesis ];