diff --git a/web/account/siwe.react.js b/web/account/siwe.react.js
--- a/web/account/siwe.react.js
+++ b/web/account/siwe.react.js
@@ -2,6 +2,7 @@
 
 import '@rainbow-me/rainbowkit/dist/index.css';
 
+import olm from '@matrix-org/olm';
 import {
   ConnectButton,
   darkTheme,
@@ -28,8 +29,8 @@
 } from 'lib/utils/action-utils';
 import {
   createSIWEMessage,
+  getSIWEStatementForPublicKey,
   siweMessageSigningExplanationStatements,
-  siweStatementWithoutPublicKey,
 } from 'lib/utils/siwe-utils.js';
 
 import Button from '../components/button.react';
@@ -55,6 +56,10 @@
   const logInExtraInfo = useSelector(webLogInExtraInfoSelector);
 
   const [siweNonce, setSIWENonce] = React.useState<?string>(null);
+  const [
+    primaryIdentityPublicKey,
+    setPrimaryIdentityPublicKey,
+  ] = React.useState<?string>(null);
   const [
     hasSIWEButtonBeenClicked,
     setHasSIWEButtonBeenClicked,
@@ -78,6 +83,16 @@
     );
   }, [dispatchActionPromise, getSIWENonceCall, siweNonceShouldBeFetched]);
 
+  React.useEffect(() => {
+    (async () => {
+      await olm.init();
+      const account = new olm.Account();
+      account.create();
+      const { ed25519 } = JSON.parse(account.identity_keys());
+      setPrimaryIdentityPublicKey(ed25519);
+    })();
+  }, []);
+
   const siweButtonColor = React.useMemo(
     () => ({ backgroundColor: 'white', color: 'black' }),
     [],
@@ -108,23 +123,21 @@
 
   const onSignInButtonClick = React.useCallback(async () => {
     invariant(siweNonce, 'nonce must be present during SIWE attempt');
-    const message = createSIWEMessage(
-      address,
-      siweStatementWithoutPublicKey,
-      siweNonce,
+    invariant(
+      primaryIdentityPublicKey,
+      'primaryIdentityPublicKey must be present during SIWE attempt',
     );
+    const statement = getSIWEStatementForPublicKey(primaryIdentityPublicKey);
+    const message = createSIWEMessage(address, statement, siweNonce);
     const signature = await signer.signMessage(message);
     attemptSIWEAuth(message, signature);
-  }, [address, attemptSIWEAuth, signer, siweNonce]);
+  }, [address, attemptSIWEAuth, primaryIdentityPublicKey, signer, siweNonce]);
 
   let siweLoginForm;
-  if (signer && !siweNonce) {
+  if (signer && (!siweNonce || !primaryIdentityPublicKey)) {
     siweLoginForm = (
       <div className={css.connectButtonContainer}>
-        <LoadingIndicator
-          status={getSIWENonceCallLoadingStatus}
-          size="medium"
-        />
+        <LoadingIndicator status="loading" size="medium" />
       </div>
     );
   } else if (signer) {