diff --git a/pkgs/by-name/jo/joplin-desktop/package.nix b/pkgs/by-name/jo/joplin-desktop/package.nix
index ce1c3589d199..1e293c35de84 100644
--- a/pkgs/by-name/jo/joplin-desktop/package.nix
+++ b/pkgs/by-name/jo/joplin-desktop/package.nix
@@ -228,7 +228,7 @@ stdenv.mkDerivation (finalAttrs: {
       icon = "joplin";
       comment = "Joplin for Desktop";
       categories = [ "Office" ];
-      startupWMClass = "@joplin/app-desktop";
+      startupWMClass = "joplin-app-desktop";
       mimeTypes = [ "x-scheme-handler/joplin" ];
     })
   ];