diff --git a/pkgs/development/python-modules/python-registry/default.nix b/pkgs/development/python-modules/python-registry/default.nix
index fbf8df7f322d..8b24ca08ff8b 100644
--- a/pkgs/development/python-modules/python-registry/default.nix
+++ b/pkgs/development/python-modules/python-registry/default.nix
@@ -4,6 +4,7 @@
 , fetchFromGitHub
 , pytestCheckHook
 , unicodecsv
+, six
 }:
 
 buildPythonPackage rec {
@@ -24,6 +25,7 @@ buildPythonPackage rec {
 
   checkInputs = [
     pytestCheckHook
+    six
   ];
 
   disabledTestPaths = [