diff --git a/pkgs/development/python-modules/ddt/default.nix b/pkgs/development/python-modules/ddt/default.nix
index f993c3844b8..4766d04c1f3 100644
--- a/pkgs/development/python-modules/ddt/default.nix
+++ b/pkgs/development/python-modules/ddt/default.nix
@@ -1,6 +1,7 @@
 { lib
 , buildPythonPackage
 , fetchPypi
+, fetchpatch
 , six, pyyaml, mock
 , pytestCheckHook
 , enum34
@@ -16,6 +17,14 @@ buildPythonPackage rec {
     sha256 = "0595e70d074e5777771a45709e99e9d215552fb1076443a25fad6b23d8bf38da";
   };
 
+  patches = [
+    # fix tests with recent PyYAML, https://github.com/datadriventests/ddt/pull/96
+    (fetchpatch {
+      url = "https://github.com/datadriventests/ddt/commit/97f0a2315736e50f1b34a015447cd751da66ecb6.patch";
+      sha256 = "1g7l5h7m7s4yqfxlygrg7nnhb9xhz1drjld64ssi3fbsmn7klf0a";
+    })
+  ];
+
   checkInputs = [ six pyyaml mock pytestCheckHook ];
 
   propagatedBuildInputs = lib.optionals (!isPy3k) [