diff --git a/res/css/views/elements/_Dropdown.scss b/res/css/views/elements/_Dropdown.scss
index 0dd9656c9c..32a68d5252 100644
--- a/res/css/views/elements/_Dropdown.scss
+++ b/res/css/views/elements/_Dropdown.scss
@@ -33,6 +33,10 @@ limitations under the License.
     user-select: none;
 }
 
+.mx_Dropdown_input.mx_AccessibleButton_disabled {
+    cursor: not-allowed;
+}
+
 .mx_Dropdown_input:focus {
     border-color: $input-focused-border-color;
 }
diff --git a/src/components/structures/auth/Login.js b/src/components/structures/auth/Login.js
index 851ea30ba0..5d3cb69417 100644
--- a/src/components/structures/auth/Login.js
+++ b/src/components/structures/auth/Login.js
@@ -687,7 +687,7 @@ export default createReactClass({
 
         return (
             <AuthPage>
-                <AuthHeader />
+                <AuthHeader disableLanguageSelector={this.props.isSyncing || this.state.busyLoggingIn} />
                 <AuthBody>
                     <h2>
                         {_t('Sign in')}
diff --git a/src/components/views/auth/AuthHeader.js b/src/components/views/auth/AuthHeader.js
index 133fd41359..6e787ba77c 100644
--- a/src/components/views/auth/AuthHeader.js
+++ b/src/components/views/auth/AuthHeader.js
@@ -16,12 +16,17 @@ limitations under the License.
 */
 
 import React from 'react';
+import PropTypes from 'prop-types';
 import createReactClass from 'create-react-class';
 import * as sdk from '../../../index';
 
 export default createReactClass({
     displayName: 'AuthHeader',
 
+    propTypes: {
+        disableLanguageSelector: PropTypes.bool,
+    },
+
     render: function() {
         const AuthHeaderLogo = sdk.getComponent('auth.AuthHeaderLogo');
         const LanguageSelector = sdk.getComponent('views.auth.LanguageSelector');
@@ -29,7 +34,7 @@ export default createReactClass({
         return (
             <div className="mx_AuthHeader">
                 <AuthHeaderLogo />
-                <LanguageSelector />
+                <LanguageSelector disabled={this.props.disableLanguageSelector} />
             </div>
         );
     },
diff --git a/src/components/views/auth/LanguageSelector.js b/src/components/views/auth/LanguageSelector.js
index 99578d4504..83db5d225b 100644
--- a/src/components/views/auth/LanguageSelector.js
+++ b/src/components/views/auth/LanguageSelector.js
@@ -28,12 +28,14 @@ function onChange(newLang) {
     }
 }
 
-export default function LanguageSelector() {
+export default function LanguageSelector({disabled}) {
     if (SdkConfig.get()['disable_login_language_selector']) return <div />;
 
     const LanguageDropdown = sdk.getComponent('views.elements.LanguageDropdown');
-    return <LanguageDropdown className="mx_AuthBody_language"
+    return <LanguageDropdown
+        className="mx_AuthBody_language"
         onOptionChange={onChange}
         value={getCurrentLanguage()}
+        disabled={disabled}
     />;
 }
diff --git a/src/components/views/elements/LanguageDropdown.js b/src/components/views/elements/LanguageDropdown.js
index 18a7e95e85..e37109caff 100644
--- a/src/components/views/elements/LanguageDropdown.js
+++ b/src/components/views/elements/LanguageDropdown.js
@@ -114,6 +114,7 @@ export default class LanguageDropdown extends React.Component {
             searchEnabled={true}
             value={value}
             label={_t("Language Dropdown")}
+            disabled={this.props.disabled}
         >
             { options }
         </Dropdown>;