diff --git a/kits/firestore-bigquery-export/README.md b/kits/firestore-bigquery-export/README.md
index 8ffb4e27d..02b2d827c 100644
--- a/kits/firestore-bigquery-export/README.md
+++ b/kits/firestore-bigquery-export/README.md
@@ -155,10 +155,12 @@ the instances cannot collide.
 ## Events
 
 When `EVENTARC_CHANNEL` is configured, the function publishes `onStart` and
-`onError` lifecycle events under
-`firebase.extensions.firestore-bigquery-export.v1.*`. The extension's
-`onSuccess` event is not published; see the events entry under
-"Differences from the Stream Firestore to BigQuery extension" below.
+`onError` lifecycle events. Each one is published twice, under
+`firebase.extensions.firestore-bigquery-export.v1.*` and under the legacy
+`firebase.extensions.firestore-counter.v1.*` type the extension also used, so
+triggers written against either type keep firing. The extension's `onSuccess`
+event is not published; see the events entry under "Differences from the Stream
+Firestore to BigQuery extension" below.
 
 ## Provisioning
 
@@ -252,11 +254,12 @@ queue in the console, and the two knobs that tuned that queue,
 queue handler, which is gone, so the kit publishes `onStart` and `onError`
 only.
 
-Events are published under `firebase.extensions.firestore-bigquery-export.v1.*`
-only. The extension also published a duplicate copy of every event under
-`firebase.extensions.firestore-counter.v1.*`, a historical naming mistake kept
-for backwards compatibility. If you have Eventarc triggers listening on those
-`firestore-counter` types, point them at the `firestore-bigquery-export` types.
+Every event is still published twice, once under
+`firebase.extensions.firestore-bigquery-export.v1.*` and once under
+`firebase.extensions.firestore-counter.v1.*`. The `firestore-counter` type is a
+historical naming mistake the extension kept for backwards compatibility, and
+the kit keeps it for the same reason: triggers listening on it survive the
+migration. Write new triggers against the `firestore-bigquery-export` types.
 
 ### Wildcard columns include the document ID
 
diff --git a/kits/firestore-bigquery-export/src/events.ts b/kits/firestore-bigquery-export/src/events.ts
index baa9fc03c..f03b2a8eb 100644
--- a/kits/firestore-bigquery-export/src/events.ts
+++ b/kits/firestore-bigquery-export/src/events.ts
@@ -18,13 +18,17 @@ import * as eventArc from "firebase-admin/eventarc";
 const { getEventarc } = eventArc;
 
 /**
- * Builds the Eventarc event type for this extension.
+ * Generates both the OLD and NEW event types to maintain backward compatibility.
+ *
+ * Old Event Type: firebase.extensions.firestore-counter.v1.{eventName}
+ * New Event Type: firebase.extensions.firestore-bigquery-export.v1.{eventName}
  *
  * @param eventName The name of the event (e.g., "onStart", "onError", etc.)
- * @returns The event type string.
+ * @returns An array containing both the old and new event types
  */
 const getEventTypes = (eventName: string) => [
-  `firebase.extensions.firestore-bigquery-export.v1.${eventName}`,
+  `firebase.extensions.firestore-counter.v1.${eventName}`, // OLD Event Type for backward compatibility
+  `firebase.extensions.firestore-bigquery-export.v1.${eventName}`, // NEW Event Type following the updated convention
 ];
 
 let eventChannel: eventArc.Channel | undefined;
diff --git a/kits/firestore-bigquery-export/tests/events.test.ts b/kits/firestore-bigquery-export/tests/events.test.ts
index 35057e463..18c77cde8 100644
--- a/kits/firestore-bigquery-export/tests/events.test.ts
+++ b/kits/firestore-bigquery-export/tests/events.test.ts
@@ -59,14 +59,13 @@ describe("channel configured", () => {
     setupEventChannel();
   });
 
-  test("publishes the firestore-bigquery-export event type only", async () => {
+  test("publishes both the legacy and the current event type", async () => {
     await recordStartEvent({ a: 1 });
-    expect(publish).toHaveBeenCalledTimes(1);
-    expect(publish).toHaveBeenCalledWith(
-      expect.objectContaining({
-        type: "firebase.extensions.firestore-bigquery-export.v1.onStart",
-      })
-    );
+    expect(publish).toHaveBeenCalledTimes(2);
+    expect(publish.mock.calls.map((c) => c[0].type)).toEqual([
+      "firebase.extensions.firestore-counter.v1.onStart",
+      "firebase.extensions.firestore-bigquery-export.v1.onStart",
+    ]);
   });
 
   test("error / success / completion map to their event types", async () => {
@@ -76,9 +75,24 @@ describe("channel configured", () => {
 
     const types = publish.mock.calls.map((c) => c[0].type);
     expect(types).toEqual([
+      "firebase.extensions.firestore-counter.v1.onError",
       "firebase.extensions.firestore-bigquery-export.v1.onError",
+      "firebase.extensions.firestore-counter.v1.onSuccess",
       "firebase.extensions.firestore-bigquery-export.v1.onSuccess",
+      "firebase.extensions.firestore-counter.v1.onCompletion",
       "firebase.extensions.firestore-bigquery-export.v1.onCompletion",
     ]);
   });
+
+  test("the legacy copy carries the same payload as the current one", async () => {
+    await recordErrorEvent(new Error("boom"), "doc1");
+
+    const [legacy, current] = publish.mock.calls.map((c) => c[0]);
+    expect(legacy.data).toEqual({ message: "boom" });
+    expect(legacy.subject).toBe("doc1");
+    expect({ ...legacy, type: undefined }).toEqual({
+      ...current,
+      type: undefined,
+    });
+  });
 });