diff --git a/README.md b/README.md
index 78c8157..c4a6cdd 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# XRegExp 5.1.0
+# XRegExp 5.1.1
 
 [![Build Status](https://github.com/slevithan/xregexp/workflows/Node.js%20CI/badge.svg)](https://github.com/slevithan/xregexp/actions)
 
diff --git a/package-lock.json b/package-lock.json
index a701838..837d907 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,11 +1,11 @@
 {
   "name": "xregexp",
-  "version": "5.1.0",
+  "version": "5.1.1",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
-      "version": "5.1.0",
+      "version": "5.1.1",
       "license": "MIT",
       "dependencies": {
         "@babel/runtime-corejs3": "^7.16.5"
diff --git a/package.json b/package.json
index cb7bea7..25f7dd7 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "xregexp",
-  "version": "5.1.0",
+  "version": "5.1.1",
   "description": "Extended regular expressions",
   "homepage": "http://xregexp.com/",
   "author": "Steven Levithan <steves_list@hotmail.com>",
diff --git a/src/addons/build.js b/src/addons/build.js
index 7e9ec84..281e40a 100644
--- a/src/addons/build.js
+++ b/src/addons/build.js
@@ -1,5 +1,5 @@
 /*!
- * XRegExp.build 5.1.0
+ * XRegExp.build 5.1.1
  * <xregexp.com>
  * Steven Levithan (c) 2012-present MIT License
  */
diff --git a/src/addons/matchrecursive.js b/src/addons/matchrecursive.js
index 84bbdee..057116a 100644
--- a/src/addons/matchrecursive.js
+++ b/src/addons/matchrecursive.js
@@ -1,5 +1,5 @@
 /*!
- * XRegExp.matchRecursive 5.1.0
+ * XRegExp.matchRecursive 5.1.1
  * <xregexp.com>
  * Steven Levithan (c) 2009-present MIT License
  */
diff --git a/src/addons/unicode-base.js b/src/addons/unicode-base.js
index 5b21eb6..4029176 100644
--- a/src/addons/unicode-base.js
+++ b/src/addons/unicode-base.js
@@ -1,5 +1,5 @@
 /*!
- * XRegExp Unicode Base 5.1.0
+ * XRegExp Unicode Base 5.1.1
  * <xregexp.com>
  * Steven Levithan (c) 2008-present MIT License
  */
diff --git a/src/addons/unicode-categories.js b/src/addons/unicode-categories.js
index 87c5d5a..e501689 100644
--- a/src/addons/unicode-categories.js
+++ b/src/addons/unicode-categories.js
@@ -1,5 +1,5 @@
 /*!
- * XRegExp Unicode Categories 5.1.0
+ * XRegExp Unicode Categories 5.1.1
  * <xregexp.com>
  * Steven Levithan (c) 2010-present MIT License
  * Unicode data by Mathias Bynens <mathiasbynens.be>
diff --git a/src/addons/unicode-properties.js b/src/addons/unicode-properties.js
index d79eadc..a15a924 100644
--- a/src/addons/unicode-properties.js
+++ b/src/addons/unicode-properties.js
@@ -1,5 +1,5 @@
 /*!
- * XRegExp Unicode Properties 5.1.0
+ * XRegExp Unicode Properties 5.1.1
  * <xregexp.com>
  * Steven Levithan (c) 2012-present MIT License
  * Unicode data by Mathias Bynens <mathiasbynens.be>
diff --git a/src/addons/unicode-scripts.js b/src/addons/unicode-scripts.js
index 24e0431..c71f965 100644
--- a/src/addons/unicode-scripts.js
+++ b/src/addons/unicode-scripts.js
@@ -1,5 +1,5 @@
 /*!
- * XRegExp Unicode Scripts 5.1.0
+ * XRegExp Unicode Scripts 5.1.1
  * <xregexp.com>
  * Steven Levithan (c) 2010-present MIT License
  * Unicode data by Mathias Bynens <mathiasbynens.be>
diff --git a/src/xregexp.js b/src/xregexp.js
index c7260d4..655290e 100644
--- a/src/xregexp.js
+++ b/src/xregexp.js
@@ -1,5 +1,5 @@
 /*!
- * XRegExp 5.1.0
+ * XRegExp 5.1.1
  * <xregexp.com>
  * Steven Levithan (c) 2007-present MIT License
  */
@@ -650,7 +650,7 @@ XRegExp.prototype = new RegExp();
  * @memberOf XRegExp
  * @type String
  */
-XRegExp.version = '5.1.0';
+XRegExp.version = '5.1.1';
 
 // ==--------------------------==
 // Public methods