diff --git a/pkgs/development/python-modules/rfc3986/default.nix b/pkgs/development/python-modules/rfc3986/default.nix
index b2675d04d5b0..2b1d769ea0c3 100644
--- a/pkgs/development/python-modules/rfc3986/default.nix
+++ b/pkgs/development/python-modules/rfc3986/default.nix
@@ -10,7 +10,7 @@ buildPythonPackage rec {
     sha256 = "1qf4dyxvjs7mxrxc0gr7gzyn4iflb2wgq01r5pzrxac8rnvy8fmw";
   };
 
-  buildInputs = [ pytest ];
+  checkInputs = [ pytest ];
   checkPhase = ''
     py.test
   '';