diff --git a/README.md b/README.md
index 9adc157..d5fca89 100644
--- a/README.md
+++ b/README.md
@@ -35,6 +35,8 @@ bun run your-app-entrypoint.js
 
 ## changelog
 
+- **Version 1.2.1**
+  - bugfix: check for `window` without causing error
 - **Version 1.2.0**
   - modified `frontend/index.js` such that script can now be used in SharedWorker and HTTPS contexts
 - **Version 1.1.0**
diff --git a/frontend/index.js b/frontend/index.js
index e52ebbc..f4eae2c 100644
--- a/frontend/index.js
+++ b/frontend/index.js
@@ -34,7 +34,7 @@ class FramerockUtils {
 		
 		console.debug('SETUP TRANSPORT')
 
-		const ctx_location = window ? window.location : self.location
+		const ctx_location = (typeof window !== "undefined") ? window.location : self.location
 		const ws_protocol = ctx_location.protocol === 'http:' ? 'ws:' : 'wss:'
 		
 		this._ws = new WebSocket(`${ws_protocol}//${ctx_location.host}/ws`)
diff --git a/package.json b/package.json
index 0fce878..92f3088 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "framerock",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "type": "module",
   "main": "backend/index.js"
 }