diff --git a/src/events/http/HttpServer.js b/src/events/http/HttpServer.js
index e59175770..724b676ab 100644
--- a/src/events/http/HttpServer.js
+++ b/src/events/http/HttpServer.js
@@ -439,6 +439,7 @@ export default class HttpServer {
       // payload processing
       const encoding = detectEncoding(request)
 
+      request.raw.req.payload = request.payload
       request.payload = request.payload && request.payload.toString(encoding)
       request.rawPayload = request.payload
 
diff --git a/src/events/http/lambda-events/LambdaProxyIntegrationEvent.js b/src/events/http/lambda-events/LambdaProxyIntegrationEvent.js
index 9f624bd70..30b92f124 100644
--- a/src/events/http/lambda-events/LambdaProxyIntegrationEvent.js
+++ b/src/events/http/lambda-events/LambdaProxyIntegrationEvent.js
@@ -4,6 +4,7 @@ import { env } from "node:process"
 import { log } from "@serverless/utils/log.js"
 import { decodeJwt } from "jose"
 import {
+  detectEncoding,
   formatToClfTime,
   nullIfEmpty,
   parseHeaders,
@@ -63,6 +64,7 @@ export default class LambdaProxyIntegrationEvent {
     }
 
     let body = this.#request.payload
+    let isBase64Encoded = false
 
     const { rawHeaders, url } = this.#request.raw.req
 
@@ -80,6 +82,15 @@ export default class LambdaProxyIntegrationEvent {
     }
 
     if (body) {
+      if (
+        this.#request.raw.req.payload &&
+        detectEncoding(this.#request) === "binary"
+      ) {
+        body = Buffer.from(this.#request.raw.req.payload).toString("base64")
+        headers["Content-Length"] = String(Buffer.byteLength(body, "base64"))
+        isBase64Encoded = true
+      }
+
       if (typeof body !== "string") {
         // this.#request.payload is NOT the same as the rawPayload
         body = this.#request.rawPayload
@@ -155,7 +166,7 @@ export default class LambdaProxyIntegrationEvent {
       body,
       headers,
       httpMethod,
-      isBase64Encoded: false, // TODO hook up
+      isBase64Encoded,
       multiValueHeaders: parseMultiValueHeaders(
         // NOTE FIXME request.raw.req.rawHeaders can only be null for testing (hapi shot inject())
         rawHeaders || [],
diff --git a/src/events/http/lambda-events/LambdaProxyIntegrationEventV2.js b/src/events/http/lambda-events/LambdaProxyIntegrationEventV2.js
index b072bf1e0..72551e7de 100644
--- a/src/events/http/lambda-events/LambdaProxyIntegrationEventV2.js
+++ b/src/events/http/lambda-events/LambdaProxyIntegrationEventV2.js
@@ -3,6 +3,7 @@ import { env } from "node:process"
 import { log } from "@serverless/utils/log.js"
 import { decodeJwt } from "jose"
 import {
+  detectEncoding,
   formatToClfTime,
   lowerCaseKeys,
   nullIfEmpty,
@@ -55,6 +56,7 @@ export default class LambdaProxyIntegrationEventV2 {
     }
 
     let body = this.#request.payload
+    let isBase64Encoded = false
 
     const { rawHeaders } = this.#request.raw.req
 
@@ -72,6 +74,15 @@ export default class LambdaProxyIntegrationEventV2 {
     }
 
     if (body) {
+      if (
+        this.#request.raw.req.payload &&
+        detectEncoding(this.#request) === "binary"
+      ) {
+        body = Buffer.from(this.#request.raw.req.payload).toString("base64")
+        headers["content-length"] = String(Buffer.byteLength(body, "base64"))
+        isBase64Encoded = true
+      }
+
       if (typeof body !== "string") {
         // this.#request.payload is NOT the same as the rawPayload
         body = this.#request.rawPayload
@@ -145,7 +156,7 @@ export default class LambdaProxyIntegrationEventV2 {
       body,
       cookies,
       headers,
-      isBase64Encoded: false,
+      isBase64Encoded,
       pathParameters: nullIfEmpty(pathParams),
       queryStringParameters: this.#request.url.search
         ? parseQueryStringParametersForPayloadV2(this.#request.url.searchParams)
diff --git a/tests/integration/httpApi-headers/httpApi-headers.test.js b/tests/integration/httpApi-headers/httpApi-headers.test.js
index 1ca82ed8f..f6db7de2b 100644
--- a/tests/integration/httpApi-headers/httpApi-headers.test.js
+++ b/tests/integration/httpApi-headers/httpApi-headers.test.js
@@ -1,4 +1,5 @@
 import assert from "node:assert"
+import { Buffer } from "node:buffer"
 import { join } from "desm"
 import { setup, teardown } from "../../_testHelpers/index.js"
 import { BASE_URL } from "../../config.js"
@@ -13,15 +14,60 @@ describe("HttpApi Headers Tests", function desc() {
   afterEach(() => teardown())
 
   //
-  ;["GET", "POST"].forEach((method) => {
-    it(`${method} headers`, async () => {
-      const url = new URL("/echo-headers", BASE_URL)
+  ;[
+    {
+      desiredContentLengthHeader: "Content-Length",
+      desiredOriginHeader: "Origin",
+      desiredWebhookSignatureHeder: "X-Webhook-Signature",
+      payloadVersion: "1.0",
+    },
+    {
+      desiredContentLengthHeader: "content-length",
+      desiredOriginHeader: "origin",
+      desiredWebhookSignatureHeder: "x-webhook-signature",
+      payloadVersion: "2.0",
+    },
+  ].forEach((t) => {
+    ;["GET", "POST"].forEach((method) => {
+      it(`${method} headers (payload ${t.payloadVersion})`, async () => {
+        const url = new URL(`/echo-headers-${t.payloadVersion}`, BASE_URL)
+        const options = {
+          headers: {
+            Origin: "http://www.example.com",
+            "X-Webhook-Signature": "ABCDEF",
+          },
+          method,
+        }
+
+        const response = await fetch(url, options)
+
+        assert.equal(response.status, 200)
+
+        const body = await response.json()
+
+        assert.equal(
+          body.headersReceived[t.desiredOriginHeader],
+          "http://www.example.com",
+        )
+        assert.equal(
+          body.headersReceived[t.desiredWebhookSignatureHeder],
+          "ABCDEF",
+        )
+        assert.equal(body.isBase64EncodedReceived, false)
+      })
+    })
+
+    it(`multipart/form-data headers are base64 encoded (payload ${t.payloadVersion})`, async () => {
+      const url = new URL(`/echo-headers-${t.payloadVersion}`, BASE_URL)
       const options = {
+        body: `------WebKitFormBoundary7MA4YWxkTrZu0gW\r\nContent-Disposition: form-data; name="file"; filename="file.txt"\r\nContent-Type: text/plain\r\n\r\n\u0001content\u0003\r\n------WebKitFormBoundary7MA4YWxkTrZu0gW--\r\n`,
         headers: {
+          "Content-Type":
+            "multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW",
           Origin: "http://www.example.com",
           "X-Webhook-Signature": "ABCDEF",
         },
-        method,
+        method: "POST",
       }
 
       const response = await fetch(url, options)
@@ -30,8 +76,23 @@ describe("HttpApi Headers Tests", function desc() {
 
       const body = await response.json()
 
-      assert.equal(body.headersReceived.origin, "http://www.example.com")
-      assert.equal(body.headersReceived["x-webhook-signature"], "ABCDEF")
+      assert.equal(
+        body.headersReceived[t.desiredOriginHeader],
+        "http://www.example.com",
+      )
+      assert.equal(
+        body.headersReceived[t.desiredWebhookSignatureHeder],
+        "ABCDEF",
+      )
+      assert.equal(
+        Number.parseInt(body.headersReceived[t.desiredContentLengthHeader], 10),
+        options.body.length,
+      )
+      assert.equal(body.isBase64EncodedReceived, true)
+      assert.equal(
+        body.bodyReceived,
+        Buffer.from(options.body).toString("base64"),
+      )
     })
   })
 })
diff --git a/tests/integration/httpApi-headers/serverless.yml b/tests/integration/httpApi-headers/serverless.yml
index df7b20010..a142fb73a 100644
--- a/tests/integration/httpApi-headers/serverless.yml
+++ b/tests/integration/httpApi-headers/serverless.yml
@@ -9,8 +9,6 @@ plugins:
 provider:
   architecture: arm64
   deploymentMethod: direct
-  httpApi:
-    payload: "2.0"
   memorySize: 1024
   name: aws
   region: us-east-1
@@ -19,12 +17,25 @@ provider:
   versionFunctions: false
 
 functions:
+  echoHeadersV1:
+    httpApi:
+      payload: "1.0"
+    events:
+      - httpApi:
+          method: get
+          path: /echo-headers-1.0
+      - httpApi:
+          method: post
+          path: /echo-headers-1.0
+    handler: src/handler.echoHeaders
   echoHeaders:
+    httpApi:
+      payload: "2.0"
     events:
       - httpApi:
           method: get
-          path: /echo-headers
+          path: /echo-headers-2.0
       - httpApi:
           method: post
-          path: /echo-headers
+          path: /echo-headers-2.0
     handler: src/handler.echoHeaders
diff --git a/tests/integration/httpApi-headers/src/handler.js b/tests/integration/httpApi-headers/src/handler.js
index a4ccc8631..ef4c44900 100644
--- a/tests/integration/httpApi-headers/src/handler.js
+++ b/tests/integration/httpApi-headers/src/handler.js
@@ -3,7 +3,9 @@ const { stringify } = JSON
 export async function echoHeaders(event) {
   return {
     body: stringify({
+      bodyReceived: event.body,
       headersReceived: event.headers,
+      isBase64EncodedReceived: event.isBase64Encoded,
     }),
     statusCode: 200,
   }