diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2cf32dd8..b7fef565 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## [v1.3.1](https://github.com/chimurai/http-proxy-middleware/releases/tag/v1.3.1)
+
+- fix(fix-request-body): make sure the content-type exists ([#578](https://github.com/chimurai/http-proxy-middleware/pull/578)) ([oufeng](https://github.com/oufeng))
+
 ## [v1.3.0](https://github.com/chimurai/http-proxy-middleware/releases/tag/v1.3.0)
 
 - docs(response interceptor): align with nodejs default utf8 ([#567](https://github.com/chimurai/http-proxy-middleware/pull/567))
diff --git a/package.json b/package.json
index 66fe6a5c..15495583 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "http-proxy-middleware",
-  "version": "1.3.0",
+  "version": "1.3.1",
   "description": "The one-liner node.js proxy middleware for connect, express and browser-sync",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
diff --git a/src/handlers/fix-request-body.ts b/src/handlers/fix-request-body.ts
index 40c6c9e4..cc9d2776 100644
--- a/src/handlers/fix-request-body.ts
+++ b/src/handlers/fix-request-body.ts
@@ -17,7 +17,7 @@ export function fixRequestBody(proxyReq: ClientRequest, req: Request): void {
     proxyReq.write(bodyData);
   };
 
-  if (contentType.includes('application/json')) {
+  if (contentType && contentType.includes('application/json')) {
     writeBody(JSON.stringify(req.body));
   }