diff --git a/pkgs/development/python-modules/openapi-core/default.nix b/pkgs/development/python-modules/openapi-core/default.nix
index e41f7fd58099..8e39c899684c 100644
--- a/pkgs/development/python-modules/openapi-core/default.nix
+++ b/pkgs/development/python-modules/openapi-core/default.nix
@@ -17,6 +17,7 @@
 , django
 , djangorestframework
 , responses
+, mock
 }:
 
 buildPythonPackage rec {
@@ -54,6 +55,7 @@ buildPythonPackage rec {
     django
     djangorestframework
     responses
+    mock
   ];
 
   disabledTestPaths = [