diff --git a/regress/Makefile b/regress/Makefile
index 2905a0d0a..27c4e79e1 100644
--- a/regress/Makefile
+++ b/regress/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.71 2014/12/22 02:15:52 djm Exp $
+#	$OpenBSD: Makefile,v 1.72 2014/12/22 08:06:03 djm Exp $
 
 REGRESS_TARGETS=	unit t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t-exec
 tests:		$(REGRESS_TARGETS)
@@ -64,7 +64,8 @@ LTESTS= 	connect \
 		keys-command \
 		forward-control \
 		integrity \
-		krl
+		krl \
+		multipubkey
 #		dhgex \
 
 INTEROP_TESTS=	putty-transfer putty-ciphers putty-kex conch-ciphers
diff --git a/regress/multipubkey.sh b/regress/multipubkey.sh
new file mode 100644
index 000000000..e9d15306f
--- /dev/null
+++ b/regress/multipubkey.sh
@@ -0,0 +1,66 @@
+#	$OpenBSD: multipubkey.sh,v 1.1 2014/12/22 08:06:03 djm Exp $
+#	Placed in the Public Domain.
+
+tid="multiple pubkey"
+
+rm -f $OBJ/authorized_keys_$USER $OBJ/user_ca_key* $OBJ/user_key*
+rm -f $OBJ/authorized_principals_$USER $OBJ/cert_user_key*
+
+mv $OBJ/sshd_proxy $OBJ/sshd_proxy.orig
+mv $OBJ/ssh_proxy $OBJ/ssh_proxy.orig
+
+# Create a CA key
+${SSHKEYGEN} -q -N '' -t ed25519  -f $OBJ/user_ca_key ||\
+	fatal "ssh-keygen failed"
+
+# Make some keys and a certificate.
+${SSHKEYGEN} -q -N '' -t ed25519 -f $OBJ/user_key1 || \
+	fatal "ssh-keygen failed"
+${SSHKEYGEN} -q -N '' -t ed25519 -f $OBJ/user_key2 || \
+	fatal "ssh-keygen failed"
+${SSHKEYGEN} -q -s $OBJ/user_ca_key -I "regress user key for $USER" \
+	-z $$ -n ${USER},mekmitasdigoat $OBJ/user_key1 ||
+		fail "couldn't sign user_key1"
+# Copy the private key alongside the cert to allow better control of when
+# it is offered.
+mv $OBJ/user_key1-cert.pub $OBJ/cert_user_key1.pub
+cp -p $OBJ/user_key1 $OBJ/cert_user_key1
+
+grep -v IdentityFile $OBJ/ssh_proxy.orig > $OBJ/ssh_proxy
+
+opts="-oProtocol=2 -F $OBJ/ssh_proxy -oIdentitiesOnly=yes"
+opts="$opts -i $OBJ/cert_user_key1 -i $OBJ/user_key1 -i $OBJ/user_key2"
+
+for privsep in no yes; do
+	(
+		grep -v "Protocol"  $OBJ/sshd_proxy.orig
+		echo "Protocol 2"
+		echo "UsePrivilegeSeparation $privsep"
+		echo "AuthenticationMethods publickey,publickey"
+		echo "TrustedUserCAKeys $OBJ/user_ca_key.pub"
+		echo "AuthorizedPrincipalsFile $OBJ/authorized_principals_%u"
+ 	) > $OBJ/sshd_proxy
+
+	# Single key should fail.
+	rm -f $OBJ/authorized_principals_$USER
+	cat $OBJ/user_key1.pub > $OBJ/authorized_keys_$USER
+	${SSH} $opts proxy true && fail "ssh succeeded with key"
+
+	# Single key with same-public cert should fail.
+	echo mekmitasdigoat > $OBJ/authorized_principals_$USER
+	cat $OBJ/user_key1.pub > $OBJ/authorized_keys_$USER
+	${SSH} $opts proxy true && fail "ssh succeeded with key+cert"
+
+	# Multiple plain keys should succeed.
+	rm -f $OBJ/authorized_principals_$USER
+	cat $OBJ/user_key1.pub $OBJ/user_key2.pub > \
+	    $OBJ/authorized_keys_$USER
+	${SSH} $opts proxy true || fail "ssh failed with multiple keys"
+	# Cert and different key should succeed
+
+	# Key and different-public cert should succeed.
+	echo mekmitasdigoat > $OBJ/authorized_principals_$USER
+	cat $OBJ/user_key2.pub > $OBJ/authorized_keys_$USER
+	${SSH} $opts proxy true || fail "ssh failed with key/cert"
+done
+