diff --git a/package-lock.json b/package-lock.json
index 7a3da26..09d14f6 100644
Binary files a/package-lock.json and b/package-lock.json differ
diff --git a/package.json b/package.json
index a3da9e9..1499a78 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
     "name": "doomsday",
-    "version": "1.3.6",
+    "version": "1.3.7",
     "description": "Test your mastery of Conway's Doomsday rule.",
     "author": "Felix W. Dekker",
     "browser": "dist/bundle.js",
@@ -16,11 +16,9 @@
         "deploy": "grunt deploy"
     },
     "dependencies": {
-        "@fwdekker/template": "^0.0.18",
-        "js-cookie": "^2.2.1"
+        "@fwdekker/template": "^0.0.20"
     },
     "devDependencies": {
-        "@types/js-cookie": "^2.2.6",
         "grunt": "^1.2.1",
         "grunt-cli": "^1.3.2",
         "grunt-contrib-clean": "^2.0.0",
diff --git a/src/main/js/index.js b/src/main/js/index.js
index 471f3d5..3564ba3 100644
--- a/src/main/js/index.js
+++ b/src/main/js/index.js
@@ -1,5 +1,4 @@
 import {$, doAfterLoad, footer, header, nav} from "@fwdekker/template";
-import Cookies from "js-cookie";
 
 
 /**
@@ -152,7 +151,7 @@ class ValidatableInput {
 }
 
 /**
- * A wrapper around a `<details>` element that persists the state in a cookie.
+ * A wrapper around a `<details>` element that persists the state in local storage.
  */
 class ToggleableSection {
     /**
@@ -204,8 +203,7 @@ class ToggleableSection {
      * @private
      */
     _storeToggle() {
-        Cookies.set(`toggle-${this._name}`, "" + this.isOpened(),
-            {expires: 365 * 10, secure: true, sameSite: "lax", path: ""});
+        localStorage.setItem(`/tools/doomsday//toggle-${this._name}`, "" + this.isOpened());
     }
 
     /**
@@ -214,7 +212,7 @@ class ToggleableSection {
      * @private
      */
     _loadToggle() {
-        const target = Cookies.get(`toggle-${this._name}`);
+        const target = localStorage.getItem(`/tools/doomsday//toggle-${this._name}`);
         if (target === undefined) {
             this._storeToggle();
             return;