diff --git a/pkgs/applications/editors/emacs-24/default.nix b/pkgs/applications/editors/emacs-24/default.nix
index 5d6d576af8e..487fccfa90d 100644
--- a/pkgs/applications/editors/emacs-24/default.nix
+++ b/pkgs/applications/editors/emacs-24/default.nix
@@ -7,8 +7,8 @@
 , withGTK2 ? true, gtk2
 }:
 
-assert (libXft != null) -> libpng != null;	# probably a bug
-assert stdenv.isDarwin -> libXaw != null;	# fails to link otherwise
+assert (libXft != null) -> libpng != null;      # probably a bug
+assert stdenv.isDarwin -> libXaw != null;       # fails to link otherwise
 assert withGTK2 -> withX || stdenv.isDarwin;
 assert withGTK3 -> withX || stdenv.isDarwin;
 assert withGTK2 -> !withGTK3 && gtk2 != null;