diff --git a/exoscale/api/generator.py b/exoscale/api/generator.py
index 68cb7be..3c616eb 100644
--- a/exoscale/api/generator.py
+++ b/exoscale/api/generator.py
@@ -300,7 +300,7 @@ def _client_docstring(api_spec):
     args = {}
     for server in api_spec["servers"]:
         servers.append(server["url"])
-        for name, variable in server["variables"].items():
+        for name, variable in server.get("variables", {}).items():
             if name in args:
                 continue
             choices = "``, ``".join(map(repr, variable["enum"]))