diff --git a/pkgs/default.nix b/pkgs/default.nix
index e6d21232..6ca27e42 100644
--- a/pkgs/default.nix
+++ b/pkgs/default.nix
@@ -64,6 +64,10 @@ pkgs {
       } ''
         racket -l- raco test ${fractalide-tests-pkg.env}/share/racket/pkgs/*/modules/rkt/rkt-fbp/agents
       '';
+
+      fractalide-tests-flat = fractalide-tests.overrideAttrs (oldAttrs: {
+        buildInputs = [ fractalide.override { flat = true; } ];
+      });
     })
   ];
 }