diff --git a/cf/m4/proto.m4 b/cf/m4/proto.m4
index 618dde0..8c460ce 100644
--- a/cf/m4/proto.m4
+++ b/cf/m4/proto.m4
@@ -1910,6 +1910,8 @@ R<@> < $* @ [IPv6:::1] >
 			$: < ? $&{client_name} > < $1 @ [IPv6:::1] >
 R<@> < $* @ localhost.$m >
 			$: < ? $&{client_name} > < $1 @ localhost.$m >
+R<@> < $* @ localhost.localdomain >
+			$: < ? $&{client_name} > < $1 @ localhost.localdomain >
 ifdef(`_NO_UUCP_', `dnl',
 `R<@> < $* @ localhost.UUCP >
 			$: < ? $&{client_name} > < $1 @ localhost.UUCP >')