diff --git a/flake.nix b/flake.nix
index 718d8cd..7ef6be6 100644
--- a/flake.nix
+++ b/flake.nix
@@ -43,7 +43,10 @@
           let
             rewritePerSystem = sectionDef: (forAllSystems (system:
               builtins.mapAttrs (name: value:
-                self.legacyPackages.${system}.callPackage value {}
+                if final.isDerivation value then
+                  value
+                else
+                  self.legacyPackages.${system}.callPackage value {}
               ) sectionDef
             ));
           in