diff --git a/lib/invoker.js b/lib/invoker.js
index f92d4ca..ce3a81c 100644
--- a/lib/invoker.js
+++ b/lib/invoker.js
@@ -26,7 +26,7 @@ module.exports = function invoker(func) {
 
         // If the response is a CloudEvent, we need to convert it
         // to a Message first and respond with the headers/body
-        if (fnReturn instanceof CloudEvent) {
+        if (fnReturn instanceof CloudEvent || fnReturn.constructor?.name === 'CloudEvent') {
           try {
             const message = HTTP.binary(fnReturn);
             payload.headers = {...payload.headers, ...message.headers};
diff --git a/lib/types.d.ts b/lib/types.d.ts
index 2376003..9268ad7 100644
--- a/lib/types.d.ts
+++ b/lib/types.d.ts
@@ -5,12 +5,12 @@ import { CloudEvent } from 'cloudevents';
 /**
  * CloudEventFunction describes the function signature for a function that accepts CloudEvents.
  */
- export interface CloudEventFunction {
-  (context: Context, event: CloudEvent): CloudEventFunctionReturn;
+export interface CloudEventFunction<I=never, R=unknown> {
+  (context: Context, event?: CloudEvent<I>): CloudEventFunctionReturn<R>;
 }
 
 // CloudEventFunctionReturn is the return type for a CloudEventFunction.
-export type CloudEventFunctionReturn = Promise<CloudEvent> | CloudEvent | HTTPFunctionReturn;
+export type CloudEventFunctionReturn<T=unknown> = Promise<CloudEvent<T>> | CloudEvent<T> | HTTPFunctionReturn;
 
 /**
  * HTTPFunction describes the function signature for a function that handles
@@ -50,7 +50,7 @@ export interface Context {
     httpVersion: string;
     httpVersionMajor: number;
     httpVersionMinor: number;
-    cloudevent: CloudEvent;
+    cloudevent: CloudEvent<unknown>;
     cloudEventResponse(data: string|object): CloudEventResponse;
 }
 
diff --git a/package-lock.json b/package-lock.json
index 1d6b38c..801f56c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4219,7 +4219,8 @@
     },
     "node_modules/safe-buffer": {
       "version": "5.1.2",
-      "integrity": "sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g=="
+      "integrity": "sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g==",
+      "dev": true
     },
     "node_modules/safe-regex2": {
       "version": "2.0.0",
@@ -4864,15 +4865,14 @@
       }
     },
     "node_modules/util": {
-      "version": "0.12.4",
-      "resolved": "https://registry.npmjs.org/util/-/util-0.12.4.tgz",
-      "integrity": "sha512-bxZ9qtSlGUWSOy9Qa9Xgk11kSslpuZwaxCg4sNIDj6FLucDab2JxnHwyNTCpHMtK1MjoQiWQ6DiUMZYbSrO+Sw==",
+      "version": "0.12.5",
+      "resolved": "https://registry.npmjs.org/util/-/util-0.12.5.tgz",
+      "integrity": "sha512-kZf/K6hEIrWHI6XqOFUiiMa+79wE/D8Q+NCNAWclkyg3b4d2k7s0QGepNjiABc+aR3N1PAyHL7p6UcLY6LmrnA==",
       "dependencies": {
         "inherits": "^2.0.3",
         "is-arguments": "^1.0.4",
         "is-generator-function": "^1.0.7",
         "is-typed-array": "^1.1.3",
-        "safe-buffer": "^5.1.2",
         "which-typed-array": "^1.1.2"
       }
     },
@@ -8150,7 +8150,8 @@
     },
     "safe-buffer": {
       "version": "5.1.2",
-      "integrity": "sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g=="
+      "integrity": "sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g==",
+      "dev": true
     },
     "safe-regex2": {
       "version": "2.0.0",
@@ -8649,15 +8650,14 @@
       }
     },
     "util": {
-      "version": "0.12.4",
-      "resolved": "https://registry.npmjs.org/util/-/util-0.12.4.tgz",
-      "integrity": "sha512-bxZ9qtSlGUWSOy9Qa9Xgk11kSslpuZwaxCg4sNIDj6FLucDab2JxnHwyNTCpHMtK1MjoQiWQ6DiUMZYbSrO+Sw==",
+      "version": "0.12.5",
+      "resolved": "https://registry.npmjs.org/util/-/util-0.12.5.tgz",
+      "integrity": "sha512-kZf/K6hEIrWHI6XqOFUiiMa+79wE/D8Q+NCNAWclkyg3b4d2k7s0QGepNjiABc+aR3N1PAyHL7p6UcLY6LmrnA==",
       "requires": {
         "inherits": "^2.0.3",
         "is-arguments": "^1.0.4",
         "is-generator-function": "^1.0.7",
         "is-typed-array": "^1.1.3",
-        "safe-buffer": "^5.1.2",
         "which-typed-array": "^1.1.2"
       }
     },
diff --git a/test/types/context.test-d.ts b/test/types/context.test-d.ts
index 07318fa..486351b 100644
--- a/test/types/context.test-d.ts
+++ b/test/types/context.test-d.ts
@@ -18,7 +18,7 @@ expectType<string>(context.method);
 expectType<string>(context.httpVersion);
 expectType<number>(context.httpVersionMajor);
 expectType<number>(context.httpVersionMinor);
-expectType<CloudEvent>(context.cloudevent);
+expectType<CloudEvent<unknown>>(context.cloudevent);
 expectAssignable<Record<string, any>|string|undefined>(context.body);
 
 // CloudEventResponse
diff --git a/test/types/index.test-d.ts b/test/types/index.test-d.ts
index 7ce1fe4..13a65fe 100644
--- a/test/types/index.test-d.ts
+++ b/test/types/index.test-d.ts
@@ -6,10 +6,10 @@ import { CloudEvent } from 'cloudevents';
 
 const fn: Invokable = function(
   context: Context,
-  cloudevent?: CloudEvent
+  cloudevent?: CloudEvent<unknown>
 ) {
   expectType<Context>(context);
-  expectType<CloudEvent|undefined>(cloudevent);
+  expectType<CloudEvent<unknown>|undefined>(cloudevent);
   return undefined;
 };