diff --git a/pkgs/development/python-modules/rfc3986/default.nix b/pkgs/development/python-modules/rfc3986/default.nix
index 2b1d769ea0c3..4ffb182626c3 100644
--- a/pkgs/development/python-modules/rfc3986/default.nix
+++ b/pkgs/development/python-modules/rfc3986/default.nix
@@ -12,7 +12,7 @@ buildPythonPackage rec {
 
   checkInputs = [ pytest ];
   checkPhase = ''
-    py.test
+    pytest
   '';
 
   meta = with stdenv.lib; {