diff --git a/pkgs/desktops/lomiri/development/libusermetrics/default.nix b/pkgs/desktops/lomiri/development/libusermetrics/default.nix
index a73b1198349d..dc1b5c7ed950 100644
--- a/pkgs/desktops/lomiri/development/libusermetrics/default.nix
+++ b/pkgs/desktops/lomiri/development/libusermetrics/default.nix
@@ -76,7 +76,7 @@ stdenv.mkDerivation (finalAttrs: {
   ];
 
   # Tests need to be able to check locale
-  LC_ALL = lib.optionalString finalAttrs.finalPackage.doCheck "en_US.UTF-8";
+  env.LC_ALL = lib.optionalString finalAttrs.finalPackage.doCheck "en_US.UTF-8";
 
   nativeCheckInputs = [
     dbus