diff --git a/doc/developer.texi b/doc/developer.texi
index a30cc9dfaa..54c1ec667a 100644
--- a/doc/developer.texi
+++ b/doc/developer.texi
@@ -229,7 +229,7 @@ set softtabstop=4
 set cindent
 set cinoptions=(0
 " Allow tabs in Makefiles.
-autocmd FileType make set noexpandtab shiftwidth=8 softtabstop=8
+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/