diff --git a/pkgs/by-name/fi/firefoxpwa/package.nix b/pkgs/by-name/fi/firefoxpwa/package.nix
index 57f7b0a7fc5c..3f6c43bc42e4 100644
--- a/pkgs/by-name/fi/firefoxpwa/package.nix
+++ b/pkgs/by-name/fi/firefoxpwa/package.nix
@@ -56,8 +56,10 @@ rustPlatform.buildRustPackage rec {
   ];
   buildInputs = [ openssl ];
 
-  FFPWA_EXECUTABLES = ""; # .desktop entries generated without any store path references
-  FFPWA_SYSDATA = "${placeholder "out"}/share/firefoxpwa";
+  env = {
+    FFPWA_EXECUTABLES = ""; # .desktop entries generated without any store path references
+    FFPWA_SYSDATA = "${placeholder "out"}/share/firefoxpwa";
+  };
   completions = "target/${stdenv.targetPlatform.config}/release/completions";
 
   gtk_modules = map (x: x + x.gtkModule) [ libcanberra-gtk3 ];