diff --git a/src/code_runner.js b/src/code_runner.js
index 0b4cf3f..cc6e5b3 100644
--- a/src/code_runner.js
+++ b/src/code_runner.js
@@ -5,7 +5,7 @@ export class CodeRunner {
         this.isRunning = false;
         this.evalScope = {};
 
-        window.playgroundConsole = this.console;
+        globalThis.playgroundConsole = this.console;
     }
 
     setCode(code) {
@@ -48,13 +48,13 @@ export class CodeRunner {
     }
 
     evaluateCode(code) {
-        // Move evalScope to window
-        const oldWindow = {};
+        // Move evalScope to globalThis
+        const oldGlobalThis = {};
         for (const prop in this.evalScope) {
-            if (!this.evalScope.hasOwnProperty(prop)) continue;
+            if (!Object.hasOwn(this.evalScope, prop)) continue;
 
-            oldWindow[prop] = window[prop];
-            window[prop] = this.evalScope[prop];
+            oldGlobalThis[prop] = globalThis[prop];
+            globalThis[prop] = this.evalScope[prop];
         }
 
         // Evaluate code
@@ -75,10 +75,10 @@ export class CodeRunner {
         }
 
         // Restore old window props
-        for (const prop in oldWindow) {
-            if (!oldWindow.hasOwnProperty(prop)) continue;
+        for (const prop in oldGlobalThis) {
+            if (!Object.hasOwn(globalThis, prop)) continue;
 
-            window[prop] = oldWindow[prop];
+            globalThis[prop] = oldGlobalThis[prop];
         }
     }
 }
diff --git a/src/gesundheit.js b/src/gesundheit.js
index f06a9db..2138146 100644
--- a/src/gesundheit.js
+++ b/src/gesundheit.js
@@ -25,7 +25,7 @@ export class Gesundheit {
             };
 
             const assetStore = transaction.objectStore("asset");
-            const req = assetStore.add({
+            const _req = assetStore.add({
                 name: "idk",
                 mime: "idk",
                 bytes: [],
diff --git a/src/playground_console.js b/src/playground_console.js
index e25a640..802e761 100644
--- a/src/playground_console.js
+++ b/src/playground_console.js
@@ -3,7 +3,7 @@ export class PlaygroundConsole {
         this.elem = elem;
 
         // Used within error stack traces
-        window.gotoLine = (line, col) => {
+        globalThis.gotoLine = (line, col) => {
             editor.gotoLine(line, col, true);
             editor.focus();
         };
@@ -11,7 +11,7 @@ export class PlaygroundConsole {
 
     #formatStacktrace(stack) {
         return stack
-            .replaceAll(window.origin + "/", "")
+            .replaceAll(globalThis.origin + "/", "")
             .replace(
                 /data:text\/javascript;charset=utf-8,[^:]+:(\d+):(\d+)/g,
                 "<a href='javascript:gotoLine($1,$2)'>karlkoder-playground:$1:$2</a>",
@@ -30,7 +30,7 @@ export class PlaygroundConsole {
         return typeof arg;
     }
 
-    #addKeyValue(entryType, parent, property, arg) {
+    #addKeyValue(_entryType, parent, property, arg) {
         if (property) {
             const keyEl = document.createElement("span");
             keyEl.className = property === "__proto__" ? "prototype" : "property";
@@ -71,7 +71,7 @@ export class PlaygroundConsole {
                 } else {
                     // Add object properties
                     for (const prop in arg) {
-                        if (!arg.hasOwnProperty(prop)) continue;
+                        if (!Object.hasOwn(arg, prop)) continue;
 
                         this.#addEntry(
                             entryType,
diff --git a/src/text_completer.js b/src/text_completer.js
index 46e9ba7..5c9f1f3 100644
--- a/src/text_completer.js
+++ b/src/text_completer.js
@@ -53,6 +53,7 @@ const KEYWORDS = [
     "sessionStorage",
     "undefined",
     "window",
+    "globalThis",
 ];
 
 export class TextCompleter {