diff --git a/res/css/views/auth/_AuthBody.scss b/res/css/views/auth/_AuthBody.scss
index 468a4b3d62..4b2d6b1bf1 100644
--- a/res/css/views/auth/_AuthBody.scss
+++ b/res/css/views/auth/_AuthBody.scss
@@ -119,6 +119,24 @@ limitations under the License.
     margin-right: 0;
 }
 
+.mx_AuthBody_paddedFooter {
+    height: 80px; // height of the submit button + register link
+    padding-top: 28px;
+    text-align: center;
+
+    .mx_AuthBody_paddedFooter_title {
+        margin-top: 16px;
+        font-size: $font-15px;
+        line-height: $font-24px;
+    }
+
+    .mx_AuthBody_paddedFooter_subtitle {
+        margin-top: 8px;
+        font-size: $font-10px;
+        line-height: $font-14px;
+    }
+}
+
 .mx_AuthBody_changeFlow {
     display: block;
     text-align: center;
diff --git a/src/components/structures/MatrixChat.js b/src/components/structures/MatrixChat.js
index da416142f8..61b72f650b 100644
--- a/src/components/structures/MatrixChat.js
+++ b/src/components/structures/MatrixChat.js
@@ -1906,23 +1906,12 @@ export default createReactClass({
             this._onLoggedIn();
         }
 
-        // Test for the master cross-signing key in SSSS as a quick proxy for
-        // whether cross-signing has been set up on the account. We can't
-        // really continue until we know whether it's there or not so retry
-        // if this fails.
-        let masterKeyInStorage;
-        while (masterKeyInStorage === undefined) {
-            try {
-                masterKeyInStorage = !!await cli.getAccountDataFromServer("m.cross_signing.master");
-            } catch (e) {
-                if (e.errcode === "M_NOT_FOUND") {
-                    masterKeyInStorage = false;
-                } else {
-                    console.warn("Secret storage account data check failed: retrying...", e);
-                }
-            }
-        }
+        this.setState({ pendingInitialSync: true });
+        await this.firstSyncPromise.promise;
 
+        // Test for the master cross-signing key in SSSS as a quick proxy for
+        // whether cross-signing has been set up on the account.
+        const masterKeyInStorage = !!cli.getAccountData("m.cross_signing.master");
         if (masterKeyInStorage) {
             // Auto-enable cross-signing for the new session when key found in
             // secret storage.
@@ -1939,6 +1928,7 @@ export default createReactClass({
         } else {
             this._onLoggedIn();
         }
+        this.setState({ pendingInitialSync: false });
 
         return setLoggedInPromise;
     },
@@ -2060,6 +2050,7 @@ export default createReactClass({
             const Login = sdk.getComponent('structures.auth.Login');
             view = (
                 <Login
+                    isSyncing={this.state.pendingInitialSync}
                     onLoggedIn={this.onUserCompletedLoginFlow}
                     onRegisterClick={this.onRegisterClick}
                     fallbackHsUrl={this.getFallbackHsUrl()}
diff --git a/src/components/structures/auth/Login.js b/src/components/structures/auth/Login.js
index 836e5bd93d..93c93fd5ab 100644
--- a/src/components/structures/auth/Login.js
+++ b/src/components/structures/auth/Login.js
@@ -84,11 +84,13 @@ export default createReactClass({
         onServerConfigChange: PropTypes.func.isRequired,
 
         serverConfig: PropTypes.instanceOf(ValidatedServerConfig).isRequired,
+        isSyncing: PropTypes.bool,
     },
 
     getInitialState: function() {
         return {
             busy: false,
+            busyLoggingIn: null,
             errorText: null,
             loginIncorrect: false,
             canTryLogin: true, // can we attempt to log in or are there validation errors?
@@ -169,6 +171,7 @@ export default createReactClass({
                 const componentState = AutoDiscoveryUtils.authComponentStateForError(e);
                 this.setState({
                     busy: false,
+                    busyLoggingIn: false,
                     ...componentState,
                 });
                 aliveAgain = !componentState.serverErrorIsFatal;
@@ -182,6 +185,7 @@ export default createReactClass({
 
         this.setState({
             busy: true,
+            busyLoggingIn: true,
             errorText: null,
             loginIncorrect: false,
         });
@@ -250,6 +254,7 @@ export default createReactClass({
 
             this.setState({
                 busy: false,
+                busyLoggingIn: false,
                 errorText: errorText,
                 // 401 would be the sensible status code for 'incorrect password'
                 // but the login API gives a 403 https://matrix.org/jira/browse/SYN-744
@@ -594,6 +599,7 @@ export default createReactClass({
                loginIncorrect={this.state.loginIncorrect}
                serverConfig={this.props.serverConfig}
                disableSubmit={this.isBusy()}
+               hideSubmit={this.props.isSyncing || this.state.busyLoggingIn}
             />
         );
     },
@@ -629,9 +635,11 @@ export default createReactClass({
 
     render: function() {
         const Loader = sdk.getComponent("elements.Spinner");
+        const InlineSpinner = sdk.getComponent("elements.InlineSpinner");
         const AuthHeader = sdk.getComponent("auth.AuthHeader");
         const AuthBody = sdk.getComponent("auth.AuthBody");
-        const loader = this.isBusy() ? <div className="mx_Login_loader"><Loader /></div> : null;
+        const loader = this.isBusy() && !this.state.busyLoggingIn ?
+            <div className="mx_Login_loader"><Loader /></div> : null;
 
         const errorText = this.state.errorText;
 
@@ -658,6 +666,25 @@ export default createReactClass({
             );
         }
 
+        let footer;
+        if (this.props.isSyncing || this.state.busyLoggingIn) {
+            footer = <div className="mx_AuthBody_paddedFooter">
+                <div className="mx_AuthBody_paddedFooter_title">
+                    <InlineSpinner w={20} h={20} />
+                    { this.props.isSyncing ? _t("Syncing...") : _t("Signing In...") }
+                </div>
+                { this.props.isSyncing && <div className="mx_AuthBody_paddedFooter_subtitle">
+                    {_t("If you've joined lots of rooms, this might take a while")}
+                </div> }
+            </div>;
+        } else {
+            footer = (
+                <a className="mx_AuthBody_changeFlow" onClick={this.onTryRegisterClick} href="#">
+                    { _t('Create account') }
+                </a>
+            );
+        }
+
         return (
             <AuthPage>
                 <AuthHeader />
@@ -670,9 +697,7 @@ export default createReactClass({
                     { serverDeadSection }
                     { this.renderServerComponent() }
                     { this.renderLoginComponentForStep() }
-                    <a className="mx_AuthBody_changeFlow" onClick={this.onTryRegisterClick} href="#">
-                        { _t('Create account') }
-                    </a>
+                    { footer }
                 </AuthBody>
             </AuthPage>
         );
diff --git a/src/components/views/auth/PasswordLogin.js b/src/components/views/auth/PasswordLogin.js
index e64b8360c3..d27e4a8259 100644
--- a/src/components/views/auth/PasswordLogin.js
+++ b/src/components/views/auth/PasswordLogin.js
@@ -43,6 +43,7 @@ export default class PasswordLogin extends React.Component {
         onPasswordChanged: PropTypes.func,
         loginIncorrect: PropTypes.bool,
         disableSubmit: PropTypes.bool,
+        hideSubmit: PropTypes.bool,
         serverConfig: PropTypes.instanceOf(ValidatedServerConfig).isRequired,
     };
 
@@ -332,11 +333,11 @@ export default class PasswordLogin extends React.Component {
                         disabled={this.props.disableSubmit}
                     />
                     {forgotPasswordJsx}
-                    <input className="mx_Login_submit"
+                    { !this.props.hideSubmit && <input className="mx_Login_submit"
                         type="submit"
                         value={_t('Sign in')}
                         disabled={this.props.disableSubmit}
-                    />
+                    /> }
                 </form>
             </div>
         );