diff --git a/pkgs/applications/editors/emacs/elisp-packages/manual-packages/prolog/default.nix b/pkgs/applications/editors/emacs/elisp-packages/manual-packages/prolog/default.nix
index 07d234ae8942..41c9363fbf4a 100644
--- a/pkgs/applications/editors/emacs/elisp-packages/manual-packages/prolog/default.nix
+++ b/pkgs/applications/editors/emacs/elisp-packages/manual-packages/prolog/default.nix
@@ -1,4 +1,8 @@
-{ lib, melpaBuild, fetchurl }:
+{
+  lib,
+  melpaBuild,
+  fetchurl,
+}:
 
 melpaBuild {
   pname = "prolog-mode";