diff --git a/test/test-utils/test-utils.ts b/test/test-utils/test-utils.ts
index ad00f79f05..35823af88c 100644
--- a/test/test-utils/test-utils.ts
+++ b/test/test-utils/test-utils.ts
@@ -176,6 +176,7 @@ export function createTestClient(): MatrixClient {
         isUserIgnored: jest.fn().mockReturnValue(false),
         getCapabilities: jest.fn().mockResolvedValue({}),
         supportsThreads: () => false,
+        supportsIntentionalMentions: () => false,
         getRoomUpgradeHistory: jest.fn().mockReturnValue([]),
         getOpenIdToken: jest.fn().mockResolvedValue(undefined),
         registerWithIdentityServer: jest.fn().mockResolvedValue({}),