diff --git a/README.md b/README.md
index aeeb21661..8977585cb 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Mattermost Mobile
 
-**Supported Server Versions:** 3.8+
+**Supported Server Versions:** 4.0+
 
 Mattermost is an open source Slack-alternative used by thousands of companies around the world in 11 languages. Learn more at https://mattermost.com.
 
diff --git a/app/components/emoji/emoji.js b/app/components/emoji/emoji.js
index 33e80b2af..1198ff5cd 100644
--- a/app/components/emoji/emoji.js
+++ b/app/components/emoji/emoji.js
@@ -8,7 +8,7 @@ import {Image, Text} from 'react-native';
 import CustomPropTypes from 'app/constants/custom_prop_types';
 import {EmojiIndicesByAlias, Emojis} from 'app/utils/emojis';
 
-import {Client} from 'mattermost-redux/client';
+import {Client4} from 'mattermost-redux/client';
 
 export default class Emoji extends React.PureComponent {
     static propTypes = {
@@ -18,13 +18,13 @@ export default class Emoji extends React.PureComponent {
         padding: PropTypes.number,
         size: PropTypes.number.isRequired,
         textStyle: CustomPropTypes.Style
-    }
+    };
 
     static defaultProps = {
         customEmojis: new Map(),
         literal: '',
         padding: 10
-    }
+    };
 
     render() {
         const {
@@ -39,10 +39,10 @@ export default class Emoji extends React.PureComponent {
         let imageUrl;
         if (EmojiIndicesByAlias.has(emojiName)) {
             const emoji = Emojis[EmojiIndicesByAlias.get(emojiName)];
-            imageUrl = Client.getSystemEmojiImageUrl(emoji.filename);
+            imageUrl = Client4.getSystemEmojiImageUrl(emoji.filename);
         } else if (customEmojis.has(emojiName)) {
             const emoji = customEmojis.get(emojiName);
-            imageUrl = Client.getCustomEmojiImageUrl(emoji.id);
+            imageUrl = Client4.getCustomEmojiImageUrl(emoji.id);
         }
 
         if (!imageUrl) {
diff --git a/app/components/file_attachment_list/file_attachment_image.js b/app/components/file_attachment_list/file_attachment_image.js
index 214a1308e..4684d8395 100644
--- a/app/components/file_attachment_list/file_attachment_image.js
+++ b/app/components/file_attachment_list/file_attachment_image.js
@@ -11,7 +11,7 @@ import {
     StyleSheet
 } from 'react-native';
 
-import {Client} from 'mattermost-redux/client';
+import {Client4} from 'mattermost-redux/client';
 
 import imageIcon from 'assets/images/icons/image.png';
 
@@ -105,12 +105,12 @@ export default class FileAttachmentImage extends PureComponent {
 
         switch (imageSize) {
         case IMAGE_SIZE.Fullsize:
-            return Client.getFileUrl(file.id, this.state.timestamp);
+            return Client4.getFileUrl(file.id, this.state.timestamp);
         case IMAGE_SIZE.Preview:
-            return Client.getFilePreviewUrl(file.id, this.state.timestamp);
+            return Client4.getFilePreviewUrl(file.id, this.state.timestamp);
         case IMAGE_SIZE.Thumbnail:
         default:
-            return Client.getFileThumbnailUrl(file.id, this.state.timestamp);
+            return Client4.getFileThumbnailUrl(file.id, this.state.timestamp);
         }
     };
 
@@ -123,7 +123,7 @@ export default class FileAttachmentImage extends PureComponent {
         }
 
         return newWidth;
-    }
+    };
 
     render() {
         const {
diff --git a/app/components/profile_picture/profile_picture.js b/app/components/profile_picture/profile_picture.js
index d289cc7d3..76bc754a1 100644
--- a/app/components/profile_picture/profile_picture.js
+++ b/app/components/profile_picture/profile_picture.js
@@ -10,7 +10,7 @@ import {makeStyleSheetFromTheme} from 'app/utils/theme';
 
 import placeholder from 'assets/images/profile.jpg';
 
-import {Client} from 'mattermost-redux/client';
+import {Client4} from 'mattermost-redux/client';
 
 const statusToIcon = {
     online: 'check',
@@ -54,7 +54,7 @@ export default class ProfilePicture extends PureComponent {
 
         let pictureUrl;
         if (this.props.user) {
-            pictureUrl = Client.getProfilePictureUrl(this.props.user.id, this.props.user.last_picture_update);
+            pictureUrl = Client4.getProfilePictureUrl(this.props.user.id, this.props.user.last_picture_update);
         }
 
         let statusIcon;
diff --git a/app/screens/image_preview/previewer.js b/app/screens/image_preview/previewer.js
index 3f23f315b..212459c13 100644
--- a/app/screens/image_preview/previewer.js
+++ b/app/screens/image_preview/previewer.js
@@ -11,7 +11,7 @@ import {
     View,
     StyleSheet
 } from 'react-native';
-import {Client} from 'mattermost-redux/client';
+import {Client4} from 'mattermost-redux/client';
 
 import imageIcon from 'assets/images/icons/image.png';
 
@@ -179,12 +179,12 @@ export default class Previewer extends Component {
     handleGetImageURL = () => {
         const {file} = this.props;
 
-        return Client.getFilePreviewUrl(file.id, this.state.timestamp);
+        return Client4.getFilePreviewUrl(file.id, this.state.timestamp);
     };
 
     attachImageView = (c) => {
         this.imageView = c;
-    }
+    };
 
     handleZoom = (zoom) => {
         this.setState({
@@ -192,14 +192,14 @@ export default class Previewer extends Component {
         });
 
         this.props.onZoom(zoom);
-    }
+    };
 
     toggleZoom = (x, y) => {
         const zoom = !this.state.isZooming;
 
         this.imageView.setZoom(zoom, x, y);
         this.handleZoom(zoom);
-    }
+    };
 
     render() {
         const {
diff --git a/assets/base/config.json b/assets/base/config.json
index 66b69fe3a..50c9d6657 100644
--- a/assets/base/config.json
+++ b/assets/base/config.json
@@ -3,7 +3,7 @@
     "TestServerUrl": "http://localhost:8065",
     "DefaultTheme": "default",
     "ShowErrorsList": false,
-    "MinServerVersion": "3.10.0",
+    "MinServerVersion": "4.0.0",
     "PlatformNoticeURL": "https://about.mattermost.com/platform-notice-txt/",
     "MobileNoticeURL": "https://about.mattermost.com/mobile-notice-txt/",
     "SegmentApiKey": "3MT7rAoC0OP7yy3ThzqFSAtKzmzqtUPX"
diff --git a/yarn.lock b/yarn.lock
index 8291d10cf..4350423c4 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3656,7 +3656,7 @@ makeerror@1.0.x:
 
 mattermost-redux@mattermost/mattermost-redux#master:
   version "0.0.1"
-  resolved "https://codeload.github.com/mattermost/mattermost-redux/tar.gz/3bab6079caf711debd30eed5fc5283b6f97c1aeb"
+  resolved "https://codeload.github.com/mattermost/mattermost-redux/tar.gz/09be668d27afd13ea9f3618f4c368c0d0a0db485"
   dependencies:
     deep-equal "1.0.1"
     harmony-reflect "1.5.1"