diff --git a/fe/Dockerfile.prod b/fe/Dockerfile.prod
index 3807c62..a0c2320 100644
--- a/fe/Dockerfile.prod
+++ b/fe/Dockerfile.prod
@@ -51,11 +51,13 @@ RUN echo '{ \n  "rewrites": [ \n    { "source": "**", "destination": "/index.htm
 
 # Create a script to inject environment variables at runtime
 RUN echo '#!/bin/sh\n\
-echo "window.ENV = { \
-  VITE_API_URL: \"$VITE_API_URL\", \
-  VITE_SENTRY_DSN: \"$VITE_SENTRY_DSN\", \
-  VITE_ROUTER_MODE: \"$VITE_ROUTER_MODE\" \
-}" > /app/env-config.js\n\
+cat > /app/env-config.js << EOL\n\
+window.ENV = {\n\
+  VITE_API_URL: "${VITE_API_URL}",\n\
+  VITE_SENTRY_DSN: "${VITE_SENTRY_DSN}",\n\
+  VITE_ROUTER_MODE: "${VITE_ROUTER_MODE}"\n\
+};\n\
+EOL\n\
 serve -s . -l 3000' > /app/start.sh && chmod +x /app/start.sh
 
 # Expose port 3000 (serve default)