@@ -4,7 +4,6 @@ package main

 import (

 	"bytes"

-	"crypto/x509"

 	"encoding/json"

 	"encoding/pem"

 	"fmt"

@@ -25,6 +24,7 @@ import (

 	"github.com/docker/libnetwork/driverapi"

 	"github.com/docker/libnetwork/ipamapi"

 	remoteipam "github.com/docker/libnetwork/ipams/remote/api"

+	"github.com/docker/swarmkit/ca/keyutils"

 	"github.com/go-check/check"

 	"github.com/gotestyourself/gotestyourself/fs"

 	"github.com/gotestyourself/gotestyourself/icmd"

@@ -1007,7 +1007,7 @@ func checkKeyIsEncrypted(d *daemon.Swarm) func(*check.C) (interface{}, check.Com

 			return fmt.Errorf("invalid PEM-encoded private key"), nil

 		}

-		return x509.IsEncryptedPEMBlock(keyBlock), nil

+		return keyutils.IsEncryptedPEMBlock(keyBlock), nil

 	}

 }