diff --git a/lib/coding-agent/__tests__/onMergeTestToMainAction.test.ts b/lib/coding-agent/__tests__/onMergeTestToMainAction.test.ts
index b76c6be1..8405b85f 100644
--- a/lib/coding-agent/__tests__/onMergeTestToMainAction.test.ts
+++ b/lib/coding-agent/__tests__/onMergeTestToMainAction.test.ts
@@ -19,10 +19,10 @@ function createMockBot() {
 }
 
 describe("registerOnMergeTestToMainAction", () => {
-  it("registers merge_test_to_main: action handler", () => {
+  it("registers catch-all action handler", () => {
     const bot = createMockBot();
     registerOnMergeTestToMainAction(bot);
-    expect(bot.onAction).toHaveBeenCalledWith("merge_test_to_main:", expect.any(Function));
+    expect(bot.onAction).toHaveBeenCalledWith(expect.any(Function));
   });
 
   it("merges test to main and posts success", async () => {
@@ -30,7 +30,7 @@ describe("registerOnMergeTestToMainAction", () => {
 
     const bot = createMockBot();
     registerOnMergeTestToMainAction(bot);
-    const handler = bot.onAction.mock.calls[0][1];
+    const handler = bot.onAction.mock.calls[0][0];
 
     const mockThread = { post: vi.fn() };
 
@@ -45,7 +45,7 @@ describe("registerOnMergeTestToMainAction", () => {
 
     const bot = createMockBot();
     registerOnMergeTestToMainAction(bot);
-    const handler = bot.onAction.mock.calls[0][1];
+    const handler = bot.onAction.mock.calls[0][0];
 
     const mockThread = { post: vi.fn() };
 
@@ -61,7 +61,7 @@ describe("registerOnMergeTestToMainAction", () => {
 
     const bot = createMockBot();
     registerOnMergeTestToMainAction(bot);
-    const handler = bot.onAction.mock.calls[0][1];
+    const handler = bot.onAction.mock.calls[0][0];
 
     const mockThread = { post: vi.fn() };
 
diff --git a/lib/coding-agent/handlers/onMergeTestToMainAction.ts b/lib/coding-agent/handlers/onMergeTestToMainAction.ts
index ad4f0209..57932baa 100644
--- a/lib/coding-agent/handlers/onMergeTestToMainAction.ts
+++ b/lib/coding-agent/handlers/onMergeTestToMainAction.ts
@@ -9,7 +9,9 @@ import { parseMergeTestToMainActionId } from "../parseMergeTestToMainActionId";
  * @param bot
  */
 export function registerOnMergeTestToMainAction(bot: CodingAgentBot) {
-  bot.onAction("merge_test_to_main:", async event => {
+  bot.onAction(async event => {
+    if (!event.actionId.startsWith("merge_test_to_main:")) return;
+
     const thread = event.thread;
 
     const repo = parseMergeTestToMainActionId(event.actionId);