diff --git a/src/navigation/__tests__/linking.test.ts b/src/navigation/__tests__/linking.test.ts
index 6ed59783..88d2e0d4 100644
--- a/src/navigation/__tests__/linking.test.ts
+++ b/src/navigation/__tests__/linking.test.ts
@@ -153,6 +153,21 @@ describe('handleDeepLink', () => {
     expect(usePendingCalendarOpen.getState().consume()).toBeNull();
   });
 
+  it('switches to the signed-in account a widget event link names first', async () => {
+    const navigation = nav();
+    const url = links.event({ serverId: 'j', accountId: 'usera@example.org@mail', jmapAccountId: 'd' });
+    const link = parseDeepLink(url);
+    expect(link).toEqual({ kind: 'calendar', eventId: 'j', jmapAccountId: 'd', accountId: 'usera@example.org@mail' });
+    const switchAccount = vi.fn(async () => true);
+    await handleDeepLink(link!, { navigation: navigation as never, resolveThreadId: async () => null, switchAccount });
+    expect(switchAccount).toHaveBeenCalledWith('usera@example.org@mail');
+    expect(usePendingCalendarOpen.getState().consume()).toMatchObject({ serverId: 'j', accountId: 'd' });
+    // An account that is no longer signed in opens nothing.
+    expect(await handleDeepLink(link!, {
+      navigation: navigation as never, resolveThreadId: async () => null, switchAccount: async () => false,
+    })).toBe(false);
+  });
+
   it('parks the settings tab and opens the Settings tab', async () => {
     const navigation = nav();
     await handleDeepLink(
diff --git a/src/navigation/linking.ts b/src/navigation/linking.ts
index 7c621b4e..8b786423 100644
--- a/src/navigation/linking.ts
+++ b/src/navigation/linking.ts
@@ -36,8 +36,9 @@ export type DeepLink =
   | { kind: 'scheduled' }
   | { kind: 'search'; query: string }
   // `jmapAccountId`: the JMAP account owning the event (`?account=`), for
-  // one on a calendar shared with the user.
-  | { kind: 'calendar'; eventId?: string; date?: string; jmapAccountId?: string }
+  // one on a calendar shared with the user; `accountId`: the signed-in
+  // account it belongs to (`?appAccount=`, from widgets).
+  | { kind: 'calendar'; eventId?: string; date?: string; jmapAccountId?: string; accountId?: string }
   | { kind: 'contact'; contactId: string }
   | { kind: 'contacts' }
   | { kind: 'files' }
@@ -139,9 +140,13 @@ export function parseDeepLink(url: string): DeepLink | null {
     case 'calendar': {
       if (kind === 'event' && value) {
         const jmapAccountId = search.get('account') ?? undefined;
-        return jmapAccountId
-          ? { kind: 'calendar', eventId: decodeSegment(value), jmapAccountId }
-          : { kind: 'calendar', eventId: decodeSegment(value) };
+        const appAccountId = search.get('appAccount') ?? undefined;
+        return {
+          kind: 'calendar',
+          eventId: decodeSegment(value),
+          ...(jmapAccountId ? { jmapAccountId } : {}),
+          ...(appAccountId ? { accountId: appAccountId } : {}),
+        };
       }
       const date = [kind, value].find((s) => s && /^\d{4}-\d{2}-\d{2}$/.test(s));
       return { kind: 'calendar', date };
diff --git a/src/widgets/clicks.ts b/src/widgets/clicks.ts
index 687866ee..d490c711 100644
--- a/src/widgets/clicks.ts
+++ b/src/widgets/clicks.ts
@@ -86,8 +86,10 @@ export const links = {
   compose: (params: { to?: string; subject?: string; body?: string } = {}) =>
     `${base}compose${query({ to: params.to, subject: params.subject, body: params.body })}`,
   calendar: () => `${base}calendar`,
-  event: (e: Pick<EventItem, 'serverId' | 'jmapAccountId'>) =>
-    `${base}calendar/event/${enc(e.serverId)}${query({ account: e.jmapAccountId })}`,
+  // `account` is the JMAP account of a shared calendar (as in webmail
+  // permalinks); `appAccount` the signed-in account the event was shown for.
+  event: (e: Pick<EventItem, 'serverId' | 'jmapAccountId' | 'accountId'>) =>
+    `${base}calendar/event/${enc(e.serverId)}${query({ account: e.jmapAccountId, appAccount: e.accountId })}`,
   contacts: () => `${base}contacts`,
   files: () => `${base}files`,
   settings: (tab?: string) => `${base}settings${tab ? `/${enc(tab)}` : ''}`,