diff --git a/doc/developer.texi b/doc/developer.texi
index 682a239abb..7d39f2db88 100644
--- a/doc/developer.texi
+++ b/doc/developer.texi
@@ -221,8 +221,8 @@ set shiftwidth=4
 set softtabstop=4
 set cindent
 set cinoptions=(0
-" allow tabs in Makefiles
-autocmd FileType make set noexpandtab shiftwidth=8 softtabstop=8
+" Allow tabs in Makefiles.
+autocmd FileType make,automake set noexpandtab shiftwidth=8 softtabstop=8
 " Trailing whitespace and tabs are forbidden, so highlight them.
 highlight ForbiddenWhitespace ctermbg=red guibg=red
 match ForbiddenWhitespace /\s\+$\|\t/