diff --git a/index.html b/index.html
index b7579838d..ca136dbfe 100644
--- a/index.html
+++ b/index.html
@@ -186,7 +186,7 @@
   <div id="sidebar" class="interface">
 
     <a class="toc_title" href="#">
-      Underscore.js <span class="version">(1.13.0)</span>
+      Underscore.js <span class="version">(1.13.1)</span>
     </a>
     <ul class="toc_section">
       <li>&raquo; <a href="/jashkenas/underscore">GitHub Repository</a></li>
@@ -474,7 +474,7 @@
       <i>Underscore is an open-source component of <a href="https://documentcloud.org/">DocumentCloud</a>.</i>
     </p>
 
-    <h2>v1.13.0 Downloads <i style="padding-left: 12px; font-size:12px;">(Right-click, and use "Save As")</i></h2>
+    <h2>v1.13.1 Downloads <i style="padding-left: 12px; font-size:12px;">(Right-click, and use "Save As")</i></h2>
 
     <table>
       <tr>
@@ -518,32 +518,32 @@ <h2>v1.13.0 Downloads <i style="padding-left: 12px; font-size:12px;">(Right-clic
       </tr>
     </table>
 
-    <h2>v1.13.0 CDN URLs <i style="padding-left: 12px; font-size:12px;">(Use with <tt>&lt;script src="..."&gt;&lt;/script&gt;</tt>)</i></h2>
+    <h2>v1.13.1 CDN URLs <i style="padding-left: 12px; font-size:12px;">(Use with <tt>&lt;script src="..."&gt;&lt;/script&gt;</tt>)</i></h2>
 
     <ul>
       <li>
-        <tt>https://cdn.jsdelivr.net/npm/underscore@1.13.0/underscore-umd-min.js</tt>
+        <tt>https://cdn.jsdelivr.net/npm/underscore@1.13.1/underscore-umd-min.js</tt>
       </li>
       <li>
-        <tt>https://cdn.jsdelivr.net/npm/underscore@1.13.0/underscore-esm-min.js</tt>
+        <tt>https://cdn.jsdelivr.net/npm/underscore@1.13.1/underscore-esm-min.js</tt>
       </li>
       <li>
-        <tt>https://unpkg.com/underscore@1.13.0/underscore-umd-min.js</tt>
+        <tt>https://unpkg.com/underscore@1.13.1/underscore-umd-min.js</tt>
       </li>
       <li>
-        <tt>https://unpkg.com/underscore@1.13.0/underscore-esm-min.js</tt>
+        <tt>https://unpkg.com/underscore@1.13.1/underscore-esm-min.js</tt>
       </li>
       <li>
-        <tt>https://pagecdn.io/lib/underscore/1.13.0/underscore-umd-min.js</tt>
+        <tt>https://pagecdn.io/lib/underscore/1.13.1/underscore-umd-min.js</tt>
       </li>
       <li>
-        <tt>https://pagecdn.io/lib/underscore/1.13.0/underscore-esm-min.js</tt>
+        <tt>https://pagecdn.io/lib/underscore/1.13.1/underscore-esm-min.js</tt>
       </li>
       <li>
-        <tt>https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.13.0/underscore-umd-min.js</tt>
+        <tt>https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.13.1/underscore-umd-min.js</tt>
       </li>
       <li>
-        <tt>https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.13.0/underscore-esm-min.js</tt>
+        <tt>https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.13.1/underscore-esm-min.js</tt>
       </li>
     </ul>
 
diff --git a/modules/_setup.js b/modules/_setup.js
index 2c2b9bec5..c76be4381 100644
--- a/modules/_setup.js
+++ b/modules/_setup.js
@@ -1,5 +1,5 @@
 // Current version.
-export var VERSION = '1.13.0';
+export var VERSION = '1.13.1';
 
 // Establish the root object, `window` (`self`) in the browser, `global`
 // on the server, or `this` in some virtual machines. We use `self`
diff --git a/modules/index.js b/modules/index.js
index c740e11c5..055b6d56d 100644
--- a/modules/index.js
+++ b/modules/index.js
@@ -1,7 +1,7 @@
 // Named Exports
 // =============
 
-//     Underscore.js 1.13.0
+//     Underscore.js 1.13.1
 //     https://underscorejs.org
 //     (c) 2009-2021 Jeremy Ashkenas, Julian Gonggrijp, and DocumentCloud and Investigative Reporters & Editors
 //     Underscore may be freely distributed under the MIT license.
diff --git a/package-lock.json b/package-lock.json
index 9580e87c9..bd33267d6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "underscore",
-  "version": "1.13.0",
+  "version": "1.13.1",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index 1592e2090..de464a122 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "underscore",
   "description": "JavaScript's functional programming helper library.",
-  "version": "1.13.0",
+  "version": "1.13.1",
   "author": "Jeremy Ashkenas <jeremy@documentcloud.org>",
   "license": "MIT",
   "homepage": "https://underscorejs.org",
diff --git a/underscore-esm.js b/underscore-esm.js
index 29772c289..270a00f35 100644
--- a/underscore-esm.js
+++ b/underscore-esm.js
@@ -1,10 +1,10 @@
-//     Underscore.js 1.13.0
+//     Underscore.js 1.13.1
 //     https://underscorejs.org
 //     (c) 2009-2021 Jeremy Ashkenas, Julian Gonggrijp, and DocumentCloud and Investigative Reporters & Editors
 //     Underscore may be freely distributed under the MIT license.
 
 // Current version.
-var VERSION = '1.13.0';
+var VERSION = '1.13.1';
 
 // Establish the root object, `window` (`self`) in the browser, `global`
 // on the server, or `this` in some virtual machines. We use `self`
diff --git a/underscore-node-f.cjs b/underscore-node-f.cjs
index addb99080..05be06ec6 100644
--- a/underscore-node-f.cjs
+++ b/underscore-node-f.cjs
@@ -1,4 +1,4 @@
-//     Underscore.js 1.13.0
+//     Underscore.js 1.13.1
 //     https://underscorejs.org
 //     (c) 2009-2021 Jeremy Ashkenas, Julian Gonggrijp, and DocumentCloud and Investigative Reporters & Editors
 //     Underscore may be freely distributed under the MIT license.
@@ -6,7 +6,7 @@
 Object.defineProperty(exports, '__esModule', { value: true });
 
 // Current version.
-var VERSION = '1.13.0';
+var VERSION = '1.13.1';
 
 // Establish the root object, `window` (`self`) in the browser, `global`
 // on the server, or `this` in some virtual machines. We use `self`
diff --git a/underscore-node.cjs b/underscore-node.cjs
index 8c3064119..b129cea4d 100644
--- a/underscore-node.cjs
+++ b/underscore-node.cjs
@@ -1,4 +1,4 @@
-//     Underscore.js 1.13.0
+//     Underscore.js 1.13.1
 //     https://underscorejs.org
 //     (c) 2009-2021 Jeremy Ashkenas, Julian Gonggrijp, and DocumentCloud and Investigative Reporters & Editors
 //     Underscore may be freely distributed under the MIT license.
diff --git a/underscore-node.mjs b/underscore-node.mjs
index cd8b869a1..8969dbbe6 100644
--- a/underscore-node.mjs
+++ b/underscore-node.mjs
@@ -1,4 +1,4 @@
-//     Underscore.js 1.13.0
+//     Underscore.js 1.13.1
 //     https://underscorejs.org
 //     (c) 2009-2021 Jeremy Ashkenas, Julian Gonggrijp, and DocumentCloud and Investigative Reporters & Editors
 //     Underscore may be freely distributed under the MIT license.
diff --git a/underscore-umd.js b/underscore-umd.js
index 8cfb34b06..ffd77af96 100644
--- a/underscore-umd.js
+++ b/underscore-umd.js
@@ -7,13 +7,13 @@
     exports.noConflict = function () { global._ = current; return exports; };
   }()));
 }(this, (function () {
-  //     Underscore.js 1.13.0
+  //     Underscore.js 1.13.1
   //     https://underscorejs.org
   //     (c) 2009-2021 Jeremy Ashkenas, Julian Gonggrijp, and DocumentCloud and Investigative Reporters & Editors
   //     Underscore may be freely distributed under the MIT license.
 
   // Current version.
-  var VERSION = '1.13.0';
+  var VERSION = '1.13.1';
 
   // Establish the root object, `window` (`self`) in the browser, `global`
   // on the server, or `this` in some virtual machines. We use `self`