diff --git a/app/terraform/proxy/fastly.py b/app/terraform/proxy/fastly.py
index cba72af..89f83bd 100644
--- a/app/terraform/proxy/fastly.py
+++ b/app/terraform/proxy/fastly.py
@@ -125,7 +125,7 @@ class ProxyFastlyAutomation(ProxyAutomation):
         Constructor method.
         """
         # Requires Flask application context to read configuration
-        self.subgroup_max = min(current_app.config.get("FASTLY_MAX_BACKENDS", 5), 20)
+        self.subgroup_members_max = min(current_app.config.get("FASTLY_MAX_BACKENDS", 5), 20)
         super().__init__(*args, **kwargs)
 
     def import_state(self, state: Optional[Any]) -> None: