diff --git a/CHANGELOG.md b/CHANGELOG.md
index 354115e6..681f4d83 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,11 @@
+## [5.1.1](https://github.com/socketio/engine.io/compare/5.1.0...5.1.1) (2021-05-16)
+
+
+### Bug Fixes
+
+* properly close the websocket connection upon handshake error ([4360686](https://github.com/socketio/engine.io/commit/43606865e5299747cbb31f3ed9baf4567502a879))
+
+
 # [5.1.0](https://github.com/socketio/engine.io/compare/5.0.0...5.1.0) (2021-05-04)
 
 
diff --git a/package-lock.json b/package-lock.json
index 7486b833..dd10c2e0 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "engine.io",
-  "version": "5.1.0",
+  "version": "5.1.1",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -526,9 +526,9 @@
       "dev": true
     },
     "engine.io-client": {
-      "version": "5.1.0",
-      "resolved": "https://registry.npmjs.org/engine.io-client/-/engine.io-client-5.1.0.tgz",
-      "integrity": "sha512-nXE1q63uBs6GqygguQwE0q+gLVaEo8YN3tAJgADOyBu3gFV5XzAeBLlry9if6KiswzOnNUCUYqk47vC0g7WXRA==",
+      "version": "5.1.1",
+      "resolved": "https://registry.npmjs.org/engine.io-client/-/engine.io-client-5.1.1.tgz",
+      "integrity": "sha512-jPFpw2HLL0lhZ2KY0BpZhIJdleQcUO9W1xkIpo0h3d6s+5D6+EV/xgQw9qWOmymszv2WXef/6KUUehyxEKomlQ==",
       "dev": true,
       "requires": {
         "base64-arraybuffer": "0.1.4",
diff --git a/package.json b/package.json
index cc443580..12e3e2a0 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "engine.io",
-  "version": "5.1.0",
+  "version": "5.1.1",
   "description": "The realtime engine behind Socket.IO. Provides the foundation of a bidirectional connection between client and server",
   "main": "lib/engine.io.js",
   "author": "Guillermo Rauch <guillermo@learnboost.com>",
@@ -36,7 +36,7 @@
   "devDependencies": {
     "babel-eslint": "^8.0.2",
     "eiows": "^3.3.0",
-    "engine.io-client": "5.1.0",
+    "engine.io-client": "5.1.1",
     "engine.io-client-v3": "npm:engine.io-client@3.5.0",
     "eslint": "^4.19.1",
     "eslint-config-prettier": "^6.9.0",