diff --git a/pkgs/build-support/flutter/default.nix b/pkgs/build-support/flutter/default.nix
index 8d31482900a8..a3c25a4863e4 100644
--- a/pkgs/build-support/flutter/default.nix
+++ b/pkgs/build-support/flutter/default.nix
@@ -129,7 +129,7 @@ let
       ${postFixup}
     '';
 
-    passthru = {
+    passthru = (args.passthru or {}) // {
       inherit (deps) depsListFile;
     };
   });