diff --git a/pkgs/by-name/wa/way-edges/package.nix b/pkgs/by-name/wa/way-edges/package.nix
index 9b587e5c5cd4..0495e54e8991 100644
--- a/pkgs/by-name/wa/way-edges/package.nix
+++ b/pkgs/by-name/wa/way-edges/package.nix
@@ -30,7 +30,7 @@ rustPlatform.buildRustPackage (finalAttrs: {
     libpulseaudio
   ];
 
-  RUSTFLAGS = [
+  env.RUSTFLAGS = toString [
     "--cfg tokio_unstable"
     "--cfg tokio_uring"
   ];