diff --git a/pkgs/development/python-modules/pynacl/default.nix b/pkgs/development/python-modules/pynacl/default.nix
index 249945b03583..c23a90c095b6 100644
--- a/pkgs/development/python-modules/pynacl/default.nix
+++ b/pkgs/development/python-modules/pynacl/default.nix
@@ -12,7 +12,7 @@ buildPythonPackage rec {
   };
 
   #remove deadline from tests, see https://github.com/pyca/pynacl/issues/370
-  prePatch = ''
+  preCheck = ''
     sed -i 's/deadline=1500, //' tests/test_pwhash.py
     sed -i 's/deadline=1500, //' tests/test_aead.py
   '';