diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index a679b39d272..d8e0ef0abe2 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -19517,6 +19517,7 @@ in {
     };
 
     propagatedBuildInputs = with self; [ six pillow pymaging_png ];
+    checkInputs = [ self.mock ];
 
     meta = {
       description = "Quick Response code generation for Python";