diff --git a/pkgs/development/python-modules/mkdocs-redoc-tag/default.nix b/pkgs/development/python-modules/mkdocs-redoc-tag/default.nix
index 1b121ff00c78..0b0acf41e228 100644
--- a/pkgs/development/python-modules/mkdocs-redoc-tag/default.nix
+++ b/pkgs/development/python-modules/mkdocs-redoc-tag/default.nix
@@ -36,6 +36,8 @@ buildPythonPackage rec {
     pytestCheckHook
   ];
 
+  pytestFlags = [ "-s" ];
+
   meta = with lib; {
     description = "MkDocs plugin supports for add Redoc UI in page";
     homepage = "https://github.com/blueswen/mkdocs-redoc-tag";