diff --git a/sshd.c b/sshd.c

--- a/sshd.c

+++ b/sshd.c

@@ -1551,6 +1551,15 @@ main(int ac, char **av)

 			continue;

 		key = key_load_private(options.host_key_files[i], "", NULL);

 		pubkey = key_load_public(options.host_key_files[i], NULL);

+

+		if ((pubkey != NULL && pubkey->type == KEY_RSA1) ||

+		    (key != NULL && key->type == KEY_RSA1)) {

+			verbose("Ignoring RSA1 key %s",

+			    options.host_key_files[i]);

+			key_free(key);

+			key_free(pubkey);

+			continue;

+		}

 		if (pubkey == NULL && key != NULL)

 			pubkey = key_demote(key);

 		sensitive_data.host_keys[i] = key;