diff --git a/nginx_proxy.py b/nginx_proxy.py
index eb0bff5..4c0c19c 100755
--- a/nginx_proxy.py
+++ b/nginx_proxy.py
@@ -47,6 +47,8 @@ def analyse_env_vars(inspect_data):
     """Extracts the environment variables from the given result of an 'inspect
         container' call."""
     env_data = {}
+    if not 'Env' in inspect_data['Config'] or inspect_data['Config']['Env'] is None:
+        return env_data
     for env_var in inspect_data['Config']['Env']:
         t = env_var.split("=")
         env_data[t[0]] = t[1]