diff --git a/src/skins/vector/css/_components.scss b/src/skins/vector/css/_components.scss
index 880c105401..51dd0ada77 100644
--- a/src/skins/vector/css/_components.scss
+++ b/src/skins/vector/css/_components.scss
@@ -15,6 +15,7 @@
 @import "./matrix-react-sdk/views/dialogs/_ChatInviteDialog.scss";
 @import "./matrix-react-sdk/views/dialogs/_EncryptedEventDialog.scss";
 @import "./matrix-react-sdk/views/dialogs/_SetDisplayNameDialog.scss";
+@import "./matrix-react-sdk/views/dialogs/_UnknownDeviceDialog.scss";
 @import "./matrix-react-sdk/views/elements/_AddressSelector.scss";
 @import "./matrix-react-sdk/views/elements/_AddressTile.scss";
 @import "./matrix-react-sdk/views/elements/_DirectorySearchBox.scss";
diff --git a/src/skins/vector/css/matrix-react-sdk/views/dialogs/_UnknownDeviceDialog.scss b/src/skins/vector/css/matrix-react-sdk/views/dialogs/_UnknownDeviceDialog.scss
new file mode 100644
index 0000000000..3a9b64d159
--- /dev/null
+++ b/src/skins/vector/css/matrix-react-sdk/views/dialogs/_UnknownDeviceDialog.scss
@@ -0,0 +1,46 @@
+/*
+Copyright 2016 OpenMarket Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+.mx_UnknownDeviceDialog .mx_MemberDeviceInfo {
+    float: right;
+    clear: both;
+    padding: 0px;
+    padding-top: 8px;
+}
+
+.mx_UnknownDeviceDialog .mx_MemberDeviceInfo_textButton {
+    border: 0px;
+    height: 24px;
+    border-radius: 40px;
+    border: solid 1px $accent-color;
+    font-weight: 600;
+    font-size: 13px;
+    font-family: 'Open Sans', Arial, Helvetica, Sans-Serif;
+    margin-left: 0px;
+    margin-right: 8px;
+    padding-left: 0.5em;
+    padding-right: 0.5em;
+    width: 70px;
+    outline: none;
+    cursor: pointer;
+    color: $accent-color;
+    background-color: $primary-bg-color;
+}
+
+.mx_UnknownDeviceDialog .mx_UnknownDeviceDialog_deviceList li {
+    height: 40px;
+    border-bottom: 1px solid $primary-hairline-color;
+}
\ No newline at end of file
diff --git a/src/skins/vector/css/themes/_dark.scss b/src/skins/vector/css/themes/_dark.scss
index 4902724f2d..51930433ea 100644
--- a/src/skins/vector/css/themes/_dark.scss
+++ b/src/skins/vector/css/themes/_dark.scss
@@ -114,4 +114,4 @@ $progressbar-color: #000;
 
 .gm-scrollbar .thumb {
     filter: invert();
-}
\ No newline at end of file
+}