diff --git a/app.py b/app.py
index 211bb16..f7bb776 100644
--- a/app.py
+++ b/app.py
@@ -36,7 +36,7 @@ class User(UserMixin):
         return None
 
 
-API_URL = 'https://isolator.peterstockings.com/execute' #'http://127.0.0.1:5000/execute'
+API_URL = os.environ.get('API_URL', 'http://isolator.web:5000/execute') # 'https://isolator.peterstockings.com/execute' 'http://127.0.0.1:5000/execute'
 
 DEFAULT_FUNCTION_NAME = 'foo'