diff --git a/apps/integration-calendar-service/src/calendar-connection-lookup-evidence-identity.test.ts b/apps/integration-calendar-service/src/calendar-connection-lookup-evidence-identity.test.ts
new file mode 100644
index 00000000..3eb18407
--- /dev/null
+++ b/apps/integration-calendar-service/src/calendar-connection-lookup-evidence-identity.test.ts
@@ -0,0 +1,50 @@
+import { describe, expect, it } from 'vitest';
+import {
+  CalendarConnectionPersistenceError,
+  PostgresCalendarConnectionRepository,
+  type CalendarConnectionSqlClient,
+  type CalendarConnectionSqlResult,
+} from './calendar-connection-repository';
+
+const REQUESTED_CONNECTION_ID = '11111111-1111-4111-8111-111111111111';
+const CORRUPTED_CONNECTION_ID = '66666666-6666-4666-8666-666666666666';
+const WORKSPACE_ID = '22222222-2222-4222-8222-222222222222';
+const USER_ID = '33333333-3333-4333-8333-333333333333';
+
+class MismatchedLookupClient implements CalendarConnectionSqlClient {
+  async query<Row>(): Promise<CalendarConnectionSqlResult<Row>> {
+    const row = {
+      connection_id: CORRUPTED_CONNECTION_ID,
+      workspace_id: WORKSPACE_ID,
+      user_id: USER_ID,
+      provider_code: 'google',
+      provider_account_subject: 'provider-user-123',
+      scope_values: ['calendar.read'],
+      access_secret_handle: 'kms://life-os/calendar/access-reference-001',
+      refresh_secret_handle: 'kms://life-os/calendar/refresh-reference-001',
+      token_expires_at: new Date('2026-08-10T10:00:00.000Z'),
+      selected_calendar_identifier: 'primary',
+      connection_status: 'active',
+      created_at: new Date('2026-08-10T09:00:00.000Z'),
+      updated_at: new Date('2026-08-10T09:00:00.000Z'),
+      revoked_at: null,
+    };
+    return { rows: [row as unknown as Row], rowCount: 1 };
+  }
+}
+
+describe('Calendar connection lookup durable evidence identity', () => {
+  it('rejects a persistence row whose connection identity differs from the requested locator', async () => {
+    const repository = new PostgresCalendarConnectionRepository(
+      new MismatchedLookupClient(),
+    );
+
+    await expect(
+      repository.getActiveConnection({
+        connectionId: REQUESTED_CONNECTION_ID,
+        workspaceId: WORKSPACE_ID,
+        userId: USER_ID,
+      }),
+    ).rejects.toBeInstanceOf(CalendarConnectionPersistenceError);
+  });
+});
diff --git a/apps/integration-calendar-service/src/calendar-connection-repository.ts b/apps/integration-calendar-service/src/calendar-connection-repository.ts
index a073242c..d040097a 100644
--- a/apps/integration-calendar-service/src/calendar-connection-repository.ts
+++ b/apps/integration-calendar-service/src/calendar-connection-repository.ts
@@ -439,7 +439,12 @@ export class PostgresCalendarConnectionRepository {
       return undefined;
     }
     const connection = parseStoredConnection(row);
-    if (connection.status !== 'active') {
+    if (
+      connection.status !== 'active' ||
+      connection.connectionId !== safe.connectionId ||
+      connection.workspaceId !== safe.workspaceId ||
+      connection.userId !== safe.userId
+    ) {
       return invalidPersistence();
     }
     return connection;