diff --git a/pkgs/development/python-modules/lazy-object-proxy/default.nix b/pkgs/development/python-modules/lazy-object-proxy/default.nix
index c6e479a21b9..9eaae90f46e 100644
--- a/pkgs/development/python-modules/lazy-object-proxy/default.nix
+++ b/pkgs/development/python-modules/lazy-object-proxy/default.nix
@@ -1,7 +1,7 @@
 { lib
 , buildPythonPackage
 , fetchPypi
-, pytest
+, pytestCheckHook
 , setuptools_scm
 }:
 
@@ -14,13 +14,19 @@ buildPythonPackage rec {
     sha256 = "489000d368377571c6f982fba6497f2aa13c6d1facc40660963da62f5c379726";
   };
 
-  nativeBuildInputs = [ setuptools_scm ];
+  nativeBuildInputs = [
+    setuptools_scm
+  ];
 
-  checkInputs = [ pytest ];
-  checkPhase = ''
-    py.test tests
+  postPatch = ''
+    substituteInPlace pyproject.toml --replace ",<6.0" ""
+    substituteInPlace setup.cfg --replace ",<6.0" ""
   '';
 
+  checkInputs = [
+    pytestCheckHook
+  ];
+
   # Broken tests. Seem to be fixed upstream according to Travis.
   doCheck = false;