diff --git a/src/event-handler/index.ts b/src/event-handler/index.ts
index b3fe1f7e..10d6e7ab 100644
--- a/src/event-handler/index.ts
+++ b/src/event-handler/index.ts
@@ -6,7 +6,7 @@ import type {
   Options,
   State,
   WebhookEventHandlerError,
-} from "../types.ts";
+} from "../types.js";
 import {
   receiverOn as on,
   receiverOnAny as onAny,
diff --git a/src/event-handler/on.ts b/src/event-handler/on.ts
index 2b1f8c59..7d377200 100644
--- a/src/event-handler/on.ts
+++ b/src/event-handler/on.ts
@@ -4,7 +4,7 @@ import type {
   EmitterWebhookEventName,
   State,
   WebhookEventHandlerError,
-} from "../types.ts";
+} from "../types.js";
 
 function handleEventHandlers(
   state: State,
diff --git a/src/event-handler/receive.ts b/src/event-handler/receive.ts
index a1b7fb3c..37323f31 100644
--- a/src/event-handler/receive.ts
+++ b/src/event-handler/receive.ts
@@ -6,7 +6,7 @@ import type {
   State,
   WebhookError,
   WebhookEventHandlerError,
-} from "../types.ts";
+} from "../types.js";
 import { wrapErrorHandler } from "./wrap-error-handler.js";
 
 type EventAction = Extract<
diff --git a/src/event-handler/remove-listener.ts b/src/event-handler/remove-listener.ts
index 98c75e47..1bd5e1ac 100644
--- a/src/event-handler/remove-listener.ts
+++ b/src/event-handler/remove-listener.ts
@@ -1,4 +1,4 @@
-import type { EmitterWebhookEventName, State } from "../types.ts";
+import type { EmitterWebhookEventName, State } from "../types.js";
 
 export function removeListener(
   state: State,
diff --git a/src/index.ts b/src/index.ts
index 6a0e4125..2d12e6f1 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -12,7 +12,7 @@ import type {
   WebhookError,
   WebhookEventHandlerError,
   EmitterWebhookEventWithStringPayloadAndSignature,
-} from "./types.ts";
+} from "./types.js";
 
 export { createNodeMiddleware } from "./middleware/node/index.js";
 export { emitterEventNames } from "./generated/webhook-names.js";
diff --git a/src/middleware/node/index.ts b/src/middleware/node/index.ts
index a3aacd37..52ae744e 100644
--- a/src/middleware/node/index.ts
+++ b/src/middleware/node/index.ts
@@ -1,7 +1,7 @@
 import { createLogger } from "../../createLogger.js";
 import type { Webhooks } from "../../index.js";
 import { middleware } from "./middleware.js";
-import type { MiddlewareOptions } from "./types.ts";
+import type { MiddlewareOptions } from "./types.js";
 
 export function createNodeMiddleware(
   webhooks: Webhooks,
diff --git a/src/middleware/node/middleware.ts b/src/middleware/node/middleware.ts
index fa2026a3..4947172d 100644
--- a/src/middleware/node/middleware.ts
+++ b/src/middleware/node/middleware.ts
@@ -7,8 +7,8 @@ type ServerResponse = any;
 import type { WebhookEventName } from "@octokit/webhooks-types";
 
 import type { Webhooks } from "../../index.js";
-import type { WebhookEventHandlerError } from "../../types.ts";
-import type { MiddlewareOptions } from "./types.ts";
+import type { WebhookEventHandlerError } from "../../types.js";
+import type { MiddlewareOptions } from "./types.js";
 import { getMissingHeaders } from "./get-missing-headers.js";
 import { getPayload } from "./get-payload.js";
 import { onUnhandledRequestDefault } from "./on-unhandled-request-default.js";
diff --git a/src/verify-and-receive.ts b/src/verify-and-receive.ts
index 32cb6ebb..88f28083 100644
--- a/src/verify-and-receive.ts
+++ b/src/verify-and-receive.ts
@@ -6,7 +6,7 @@ import type {
   EmitterWebhookEvent,
   EmitterWebhookEventWithStringPayloadAndSignature,
   State,
-} from "./types.ts";
+} from "./types.js";
 
 export async function verifyAndReceive(
   state: State & { secret: string },