diff --git a/pkgs/development/python-modules/requests-aws4auth/default.nix b/pkgs/development/python-modules/requests-aws4auth/default.nix
index c54657b4bf5..f954a340b7f 100644
--- a/pkgs/development/python-modules/requests-aws4auth/default.nix
+++ b/pkgs/development/python-modules/requests-aws4auth/default.nix
@@ -1,4 +1,4 @@
-{ lib, buildPythonPackage, fetchPypi, isPy3k, requests }:
+{ lib, buildPythonPackage, fetchPypi, python, requests }:
 with lib;
 buildPythonPackage rec {
   pname = "requests-aws4auth";
@@ -9,15 +9,12 @@ buildPythonPackage rec {
     sha256 = "2950f6ff686b5a452a269076d990e4821d959b61cfac319c3d3c6daaa5db55ce";
   };
 
-  postPatch = optionalString isPy3k ''
-    sed "s/path_encoding_style/'path_encoding_style'/" \
-      -i requests_aws4auth/service_parameters.py
-  '';
-
   propagatedBuildInputs = [ requests ];
 
-  # The test fail on Python >= 3 because of module import errors.
-  doCheck = !isPy3k;
+  checkPhase = ''
+    cd requests_aws4auth
+    ${python.interpreter} test/requests_aws4auth_test.py
+  '';
 
   meta = {
     description = "Amazon Web Services version 4 authentication for the Python Requests library.";