diff --git a/overlays/nixpak/firefox.nix b/overlays/nixpak/firefox.nix
index 075b5c0..51309eb 100644
--- a/overlays/nixpak/firefox.nix
+++ b/overlays/nixpak/firefox.nix
@@ -81,6 +81,9 @@
       desktopName = "Firefox ESR";
       icon = "firefox";
       wmClass = "firefox-esr";
+      meta = prev.firefox-esr.meta // {
+        mainProgram = "firefox-esr";
+      };
     };
   in
     wrappedFirefox;