diff --git a/node_external_ip_controller_async.py b/node_external_ip_controller_async.py
index f083f29..1e6bcaf 100644
--- a/node_external_ip_controller_async.py
+++ b/node_external_ip_controller_async.py
@@ -5,7 +5,8 @@ import os
 # Configuration
 import yaml
 
-with open("gateway_services.yaml", "r") as f:
+GATEWAY_SERVICES_FILE = os.getenv("GATEWAY_SERVICES_FILE")
+with open(GATEWAY_SERVICES_FILE, "r") as f:
     gateway_services = yaml.safe_load(f)
 
 services = gateway_services["gateway_services"]