diff --git a/extensions/slack/src/monitor.test-helpers.ts b/extensions/slack/src/monitor.test-helpers.ts
index 41f9f737602..071e9508ffe 100644
--- a/extensions/slack/src/monitor.test-helpers.ts
+++ b/extensions/slack/src/monitor.test-helpers.ts
@@ -15,6 +15,8 @@ type SlackTestState = {
   replyMock: Mock<(...args: unknown[]) => unknown>;
   updateLastRouteMock: Mock<(...args: unknown[]) => unknown>;
   reactMock: Mock<(...args: unknown[]) => unknown>;
+  reactionAddMock: Mock<(...args: unknown[]) => unknown>;
+  reactionRemoveMock: Mock<(...args: unknown[]) => unknown>;
   readAllowFromStoreMock: Mock<(...args: unknown[]) => Promise<unknown>>;
   upsertPairingRequestMock: Mock<(...args: unknown[]) => Promise<unknown>>;
 };
@@ -25,6 +27,8 @@ const slackTestState: SlackTestState = vi.hoisted(() => ({
   replyMock: vi.fn(),
   updateLastRouteMock: vi.fn(),
   reactMock: vi.fn(),
+  reactionAddMock: vi.fn(),
+  reactionRemoveMock: vi.fn(),
   readAllowFromStoreMock: vi.fn(),
   upsertPairingRequestMock: vi.fn(),
 }));
@@ -88,8 +92,14 @@ function ensureSlackTestRuntime(): {
         },
       },
       reactions: {
-        add: (...args: unknown[]) => slackTestState.reactMock(...args),
-        remove: (...args: unknown[]) => slackTestState.reactMock(...args),
+        add: (...args: unknown[]) => {
+          slackTestState.reactionAddMock(...args);
+          return slackTestState.reactMock(...args);
+        },
+        remove: (...args: unknown[]) => {
+          slackTestState.reactionRemoveMock(...args);
+          return slackTestState.reactMock(...args);
+        },
       },
     };
   }
@@ -182,6 +192,8 @@ export function resetSlackTestState(config: Record<string, unknown> = defaultSla
   slackTestState.replyMock.mockReset();
   slackTestState.updateLastRouteMock.mockReset();
   slackTestState.reactMock.mockReset();
+  slackTestState.reactionAddMock.mockReset();
+  slackTestState.reactionRemoveMock.mockReset();
   slackTestState.readAllowFromStoreMock.mockReset().mockResolvedValue([]);
   slackTestState.upsertPairingRequestMock.mockReset().mockResolvedValue({
     code: "PAIRCODE",
diff --git a/extensions/slack/src/monitor.tool-result.test.ts b/extensions/slack/src/monitor.tool-result.test.ts
index 1cfbc5a4067..2db383289ee 100644
--- a/extensions/slack/src/monitor.tool-result.test.ts
+++ b/extensions/slack/src/monitor.tool-result.test.ts
@@ -19,7 +19,8 @@ import {
 const { monitorSlackProvider } = await import("./monitor/provider.js");
 
 const slackTestState = getSlackTestState();
-const { sendMock, replyMock, reactMock, upsertPairingRequestMock } = slackTestState;
+const { sendMock, replyMock, reactMock, reactionAddMock, upsertPairingRequestMock } =
+  slackTestState;
 
 beforeEach(() => {
   resetInboundDedupe();
@@ -275,7 +276,7 @@ describe("monitorSlackProvider tool results", () => {
     endsWith: string;
     includes: string;
   }) {
-    const names = reactMock.mock.calls.map(([args]) => (args as { name: string }).name);
+    const names = reactionAddMock.mock.calls.map(([args]) => (args as { name: string }).name);
     expect(names.slice(0, expected.startsWith.length)).toEqual(expected.startsWith);
     expect(names).toContain(expected.includes);
     expect(names.at(-1)).toBe(expected.endsWith);