diff --git a/src/async-components/views/dialogs/keybackup/CreateKeyBackupDialog.js b/src/async-components/views/dialogs/keybackup/CreateKeyBackupDialog.js
index f89fb17448..3a480a2579 100644
--- a/src/async-components/views/dialogs/keybackup/CreateKeyBackupDialog.js
+++ b/src/async-components/views/dialogs/keybackup/CreateKeyBackupDialog.js
@@ -53,7 +53,6 @@ function selectText(target) {
  */
 export default class CreateKeyBackupDialog extends React.PureComponent {
     static propTypes = {
-        secureSecretStorage: PropTypes.bool,
         onFinished: PropTypes.func.isRequired,
     }
 
@@ -65,7 +64,7 @@ export default class CreateKeyBackupDialog extends React.PureComponent {
         this._setZxcvbnResultTimeout = null;
 
         this.state = {
-            secureSecretStorage: props.secureSecretStorage,
+            secureSecretStorage: null,
             phase: PHASE_PASSPHRASE,
             passPhrase: '',
             passPhraseConfirm: '',
@@ -73,23 +72,20 @@ export default class CreateKeyBackupDialog extends React.PureComponent {
             downloaded: false,
             zxcvbnResult: null,
         };
-
-        if (this.state.secureSecretStorage === undefined) {
-            this.state.secureSecretStorage =
-                SettingsStore.isFeatureEnabled("feature_cross_signing");
-        }
-
-        // If we're using secret storage, skip ahead to the backing up step, as
-        // `accessSecretStorage` will handle passphrases as needed.
-        if (this.state.secureSecretStorage) {
-            this.state.phase = PHASE_BACKINGUP;
-        }
     }
 
-    componentDidMount() {
+    async componentDidMount() {
+        const cli = MatrixClientPeg.get();
+        const secureSecretStorage = (
+            SettingsStore.isFeatureEnabled("feature_cross_signing") &&
+            await cli.doesServerSupportUnstableFeature("org.matrix.e2e_cross_signing")
+        );
+        this.setState({ secureSecretStorage });
+
         // If we're using secret storage, skip ahead to the backing up step, as
         // `accessSecretStorage` will handle passphrases as needed.
-        if (this.state.secureSecretStorage) {
+        if (secureSecretStorage) {
+            this.setState({ phase: PHASE_BACKINGUP });
             this._createBackup();
         }
     }
diff --git a/src/components/views/right_panel/UserInfo.js b/src/components/views/right_panel/UserInfo.js
index 1174f45640..44770d9ccc 100644
--- a/src/components/views/right_panel/UserInfo.js
+++ b/src/components/views/right_panel/UserInfo.js
@@ -42,6 +42,7 @@ import {textualPowerLevel} from '../../../Roles';
 import MatrixClientContext from "../../../contexts/MatrixClientContext";
 import {RIGHT_PANEL_PHASES} from "../../../stores/RightPanelStorePhases";
 import EncryptionPanel from "./EncryptionPanel";
+import { useAsyncMemo } from '../../../hooks/useAsyncMemo';
 
 const _disambiguateDevices = (devices) => {
     const names = Object.create(null);
@@ -916,6 +917,12 @@ const useIsSynapseAdmin = (cli) => {
     return isAdmin;
 };
 
+const useHomeserverSupportsCrossSigning = (cli) => {
+    return useAsyncMemo(async () => {
+        return cli.doesServerSupportUnstableFeature("org.matrix.e2e_cross_signing");
+    }, [cli], false);
+};
+
 function useRoomPermissions(cli, room, user) {
     const [roomPermissions, setRoomPermissions] = useState({
         // modifyLevelMax is the max PL we can set this user to, typically min(their PL, our PL) && canSetPL
@@ -1315,19 +1322,23 @@ const BasicUserInfo = ({room, member, groupId, devices, isRoomEncrypted}) => {
         text = _t("Messages in this room are end-to-end encrypted.");
     }
 
-    const userTrust = cli.checkUserTrust(member.userId);
-    const userVerified = SettingsStore.isFeatureEnabled("feature_cross_signing") ?
-        userTrust.isCrossSigningVerified() :
-        userTrust.isVerified();
-    const isMe = member.userId === cli.getUserId();
-
     let verifyButton;
-    if (isRoomEncrypted && !userVerified && !isMe) {
-        verifyButton = (
-            <AccessibleButton className="mx_UserInfo_field" onClick={() => verifyUser(member)}>
-                {_t("Verify")}
-            </AccessibleButton>
-        );
+    const homeserverSupportsCrossSigning = useHomeserverSupportsCrossSigning(cli);
+    if (
+        SettingsStore.isFeatureEnabled("feature_cross_signing") &&
+        homeserverSupportsCrossSigning
+    ) {
+        const userTrust = cli.checkUserTrust(member.userId);
+        const userVerified = userTrust.isCrossSigningVerified();
+        const isMe = member.userId === cli.getUserId();
+
+        if (isRoomEncrypted && !userVerified && !isMe) {
+            verifyButton = (
+                <AccessibleButton className="mx_UserInfo_field" onClick={() => verifyUser(member)}>
+                    {_t("Verify")}
+                </AccessibleButton>
+            );
+        }
     }
 
     let devicesSection;
diff --git a/src/components/views/settings/CrossSigningPanel.js b/src/components/views/settings/CrossSigningPanel.js
index 6e69227844..aba2d03ad2 100644
--- a/src/components/views/settings/CrossSigningPanel.js
+++ b/src/components/views/settings/CrossSigningPanel.js
@@ -72,11 +72,14 @@ export default class CrossSigningPanel extends React.PureComponent {
         const crossSigningPublicKeysOnDevice = crossSigning.getId();
         const crossSigningPrivateKeysInStorage = await crossSigning.isStoredInSecretStorage(secretStorage);
         const secretStorageKeyInAccount = await secretStorage.hasKey();
+        const homeserverSupportsCrossSigning =
+            await cli.doesServerSupportUnstableFeature("org.matrix.e2e_cross_signing");
 
         this.setState({
             crossSigningPublicKeysOnDevice,
             crossSigningPrivateKeysInStorage,
             secretStorageKeyInAccount,
+            homeserverSupportsCrossSigning,
         });
     }
 
@@ -120,6 +123,7 @@ export default class CrossSigningPanel extends React.PureComponent {
             crossSigningPublicKeysOnDevice,
             crossSigningPrivateKeysInStorage,
             secretStorageKeyInAccount,
+            homeserverSupportsCrossSigning,
         } = this.state;
 
         let errorSection;
@@ -127,13 +131,19 @@ export default class CrossSigningPanel extends React.PureComponent {
             errorSection = <div className="error">{error.toString()}</div>;
         }
 
-        const enabled = (
+        // Whether the various keys exist on your account (but not necessarily
+        // on this device).
+        const enabledForAccount = (
             crossSigningPrivateKeysInStorage &&
             secretStorageKeyInAccount
         );
 
         let summarisedStatus;
-        if (enabled && crossSigningPublicKeysOnDevice) {
+        if (!homeserverSupportsCrossSigning) {
+            summarisedStatus = <p>{_t(
+                "Your homeserver does not support cross-signing.",
+            )}</p>;
+        } else if (enabledForAccount && crossSigningPublicKeysOnDevice) {
             summarisedStatus = <p>✅ {_t(
                 "Cross-signing and secret storage are enabled.",
             )}</p>;
@@ -149,18 +159,18 @@ export default class CrossSigningPanel extends React.PureComponent {
         }
 
         let bootstrapButton;
-        if (!enabled) {
-            bootstrapButton = <div className="mx_CrossSigningPanel_buttonRow">
-                <AccessibleButton kind="primary" onClick={this._bootstrapSecureSecretStorage}>
-                    {_t("Bootstrap cross-signing and secret storage")}
-                </AccessibleButton>
-            </div>;
-        } else {
-            bootstrapButton = <div className="mx_CrossSigningPanel_buttonRow">
+        if (enabledForAccount) {
+            bootstrapButton = (
                 <AccessibleButton kind="danger" onClick={this._destroySecureSecretStorage}>
                     {_t("Reset cross-signing and secret storage")}
                 </AccessibleButton>
-            </div>;
+            );
+        } else if (!enabledForAccount && homeserverSupportsCrossSigning) {
+            bootstrapButton = (
+                <AccessibleButton kind="primary" onClick={this._bootstrapSecureSecretStorage}>
+                    {_t("Bootstrap cross-signing and secret storage")}
+                </AccessibleButton>
+            );
         }
 
         return (
@@ -181,10 +191,16 @@ export default class CrossSigningPanel extends React.PureComponent {
                             <td>{_t("Secret storage public key:")}</td>
                             <td>{secretStorageKeyInAccount ? _t("in account data") : _t("not found")}</td>
                         </tr>
-                    </tbody></table>
+                        <tr>
+                            <td>{_t("Homeserver feature support:")}</td>
+                            <td>{homeserverSupportsCrossSigning ? _t("exists") : _t("not found")}</td>
+                        </tr>
+                   </tbody></table>
                 </details>
                 {errorSection}
-                {bootstrapButton}
+                <div className="mx_CrossSigningPanel_buttonRow">
+                    {bootstrapButton}
+                </div>
             </div>
         );
     }
diff --git a/src/components/views/settings/KeyBackupPanel.js b/src/components/views/settings/KeyBackupPanel.js
index f3fe171e63..73be2bad9f 100644
--- a/src/components/views/settings/KeyBackupPanel.js
+++ b/src/components/views/settings/KeyBackupPanel.js
@@ -127,7 +127,6 @@ export default class KeyBackupPanel extends React.PureComponent {
         Modal.createTrackedDialogAsync('Key Backup', 'Key Backup',
             import('../../../async-components/views/dialogs/keybackup/CreateKeyBackupDialog'),
             {
-                secureSecretStorage: SettingsStore.isFeatureEnabled("feature_cross_signing"),
                 onFinished: () => {
                     this._loadBackupStatus();
                 },
diff --git a/src/hooks/useAsyncMemo.js b/src/hooks/useAsyncMemo.js
new file mode 100644
index 0000000000..ef7d256b04
--- /dev/null
+++ b/src/hooks/useAsyncMemo.js
@@ -0,0 +1,25 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+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.
+*/
+
+import { useState, useEffect } from 'react';
+
+export const useAsyncMemo = (fn, deps, initialValue) => {
+    const [value, setValue] = useState(initialValue);
+    useEffect(() => {
+        fn().then(setValue);
+    }, deps); // eslint-disable-line react-hooks/exhaustive-deps
+    return value;
+};
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index 82eb660d9d..1d030f5118 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -562,11 +562,12 @@
     "New Password": "New Password",
     "Confirm password": "Confirm password",
     "Change Password": "Change Password",
+    "Your homeserver does not support cross-signing.": "Your homeserver does not support cross-signing.",
     "Cross-signing and secret storage are enabled.": "Cross-signing and secret storage are enabled.",
     "Your account has a cross-signing identity in secret storage, but it is not yet trusted by this session.": "Your account has a cross-signing identity in secret storage, but it is not yet trusted by this session.",
     "Cross-signing and secret storage are not yet set up.": "Cross-signing and secret storage are not yet set up.",
-    "Bootstrap cross-signing and secret storage": "Bootstrap cross-signing and secret storage",
     "Reset cross-signing and secret storage": "Reset cross-signing and secret storage",
+    "Bootstrap cross-signing and secret storage": "Bootstrap cross-signing and secret storage",
     "Cross-signing public keys:": "Cross-signing public keys:",
     "in memory": "in memory",
     "not found": "not found",
@@ -574,6 +575,8 @@
     "in secret storage": "in secret storage",
     "Secret storage public key:": "Secret storage public key:",
     "in account data": "in account data",
+    "Homeserver feature support:": "Homeserver feature support:",
+    "exists": "exists",
     "Your homeserver does not support session management.": "Your homeserver does not support session management.",
     "Unable to load session list": "Unable to load session list",
     "Authentication": "Authentication",