diff --git a/frontend/src/components/Chat.test.tsx b/frontend/src/components/Chat.test.tsx
index 315b826..78c6c43 100644
--- a/frontend/src/components/Chat.test.tsx
+++ b/frontend/src/components/Chat.test.tsx
@@ -631,7 +631,7 @@ describe("Chat localStorage persistence (Story 145)", () => {
 
 		// Verify sendChat was called with ALL prior messages + the new one
 		expect(lastSendChatArgs).not.toBeNull();
-		const args = lastSendChatArgs as NonNullable<typeof lastSendChatArgs>;
+		const args = lastSendChatArgs as unknown as { messages: Message[]; config: unknown };
 		expect(args.messages).toHaveLength(3);
 		expect(args.messages[0]).toEqual({
 			role: "user",
@@ -1350,7 +1350,7 @@ describe("Bug 264: Claude Code session ID persisted across browser refresh", ()
 
 		expect(lastSendChatArgs).not.toBeNull();
 		expect(
-			(lastSendChatArgs?.config as Record<string, unknown>).session_id,
+			((lastSendChatArgs as unknown as { messages: Message[]; config: unknown })?.config as Record<string, unknown>).session_id,
 		).toBe("persisted-session-xyz");
 	});