diff --git a/pkgs/by-name/ch/chatzone-desktop/package.nix b/pkgs/by-name/ch/chatzone-desktop/package.nix
index 53ea8958ed40..0ceae7faead5 100644
--- a/pkgs/by-name/ch/chatzone-desktop/package.nix
+++ b/pkgs/by-name/ch/chatzone-desktop/package.nix
@@ -30,7 +30,7 @@ stdenvNoCC.mkDerivation {
   desktopItems = [
     (makeDesktopItem {
       name = "chatzone";
-      exec = "chatzone-desktop";
+      exec = "chatzone-desktop %U";
       icon = "chatzone-desktop";
       terminal = false;
       desktopName = "Chatzone";
@@ -42,7 +42,10 @@ stdenvNoCC.mkDerivation {
         "Chat"
       ];
       startupWMClass = "Chatzone";
-      mimeTypes = [ "x-scheme-handler/mattermost" ];
+      mimeTypes = [
+        "x-scheme-handler/mattermost"
+        "x-scheme-handler/chatzone"
+      ];
     })
   ];