diff --git a/nixos/modules/services/mail/roundcube.nix b/nixos/modules/services/mail/roundcube.nix
index 22c14666a3a..0bb0eaedad5 100644
--- a/nixos/modules/services/mail/roundcube.nix
+++ b/nixos/modules/services/mail/roundcube.nix
@@ -108,6 +108,7 @@ in
       $config['max_message_size'] = '25M';
       $config['plugins'] = [${concatMapStringsSep "," (p: "'${p}'") cfg.plugins}];
       $config['des_key'] = file_get_contents('/var/lib/roundcube/des_key');
+      $config['mime_types'] = '${pkgs.nginx}/conf/mime.types';
       ${cfg.extraConfig}
     '';