diff --git a/docker-compose.yml b/docker-compose.yml
index 3115717..8ed80f6 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -16,7 +16,7 @@ services:
       context: .
       dockerfile: Dockerfile.canvas
       args:
-        - CUSTOM_VITE_WS_URL=${CUSTOM_VITE_WS_URL:-wss://excalidraw.forkless.com}
+        - CUSTOM_VITE_WS_URL=${CUSTOM_VITE_WS_URL:-excalidraw.forkless.com}
     image: celstnblacc/excalidraw-mcp-sentinel-canvas:latest
     container_name: mcp-excalidraw-canvas
     ports:
diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index c587c85..8fde057 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -435,7 +435,10 @@ function App(): JSX.Element {
       return
     }
 
-    const wsUrl = import.meta.env.CUSTOM_VITE_WS_URL || 'wss://excalidraw.forkless.com'
+    let wsUrl = import.meta.env.CUSTOM_VITE_WS_URL || 'wss://excalidraw.forkless.com'
+    if (wsUrl && !wsUrl.startsWith('ws://') && !wsUrl.startsWith('wss://')) {
+      wsUrl = 'wss://' + wsUrl
+    }
     
     websocketRef.current = new WebSocket(wsUrl)