diff --git a/provider/openstack/cinder.go b/provider/openstack/cinder.go
index 58eacea..70c8c12 100644
--- a/provider/openstack/cinder.go
+++ b/provider/openstack/cinder.go
@@ -308,7 +308,7 @@ func (s *cinderVolumeSource) attachVolume(arg storage.VolumeAttachmentParams) (*
                arg.Volume,
                arg.Machine,
                storage.VolumeAttachmentInfo{
-                       DeviceName: novaAttachment.Device[len("/dev/"):],
+                       DeviceName: (*novaAttachment.Device)[len("/dev/"):],
                },
        }, nil
 }
diff --git a/provider/openstack/provider.go b/provider/openstack/provider.go
index 84de0d4..c488a11 100644
--- a/provider/openstack/provider.go
+++ b/provider/openstack/provider.go
@@ -852,7 +852,7 @@ func (e *environ) getKeystoneDataSource(mu *sync.Mutex, datasource *simplestream
                }
        }
 
-       url, err := makeServiceURL(e.client, keystoneName, nil)
+       url, err := makeServiceURL(e.client, keystoneName, "", nil)
        if err != nil {
                return nil, errors.NewNotSupported(err, fmt.Sprintf("cannot make service URL: %v", err))
        }