diff --git a/pkgs/development/ruby-modules/bundler-env/default.nix b/pkgs/development/ruby-modules/bundler-env/default.nix
index a103dcd6ae7a..614c4719baca 100644
--- a/pkgs/development/ruby-modules/bundler-env/default.nix
+++ b/pkgs/development/ruby-modules/bundler-env/default.nix
@@ -102,7 +102,7 @@ else
     };
   in
   if copyGemFiles then
-    runCommand basicEnv.name bundlerEnvArgs ''
+    runCommand basicEnv.name (bundlerEnvArgs // { __structuredAttrs = true; }) ''
       mkdir -p $out
       for i in $paths; do
         ${buildPackages.rsync}/bin/rsync -a $i/lib $out/