diff --git a/backend/invoke_ai_web_server.py b/backend/invoke_ai_web_server.py
index 0f05dbe0ea..02e8504589 100644
--- a/backend/invoke_ai_web_server.py
+++ b/backend/invoke_ai_web_server.py
@@ -85,7 +85,14 @@ class InvokeAIWebServer:
         }
 
         if opt.cors:
-            socketio_args["cors_allowed_origins"] = opt.cors
+            _cors = opt.cors
+            # convert list back into comma-separated string,
+            # be defensive here, not sure in what form this arrives
+            if isinstance(_cors, list):
+                _cors = ",".join(_cors)
+            if "," in _cors:
+                _cors = _cors.split(",")
+            socketio_args["cors_allowed_origins"] = _cors
 
         frontend_path = self.find_frontend()
         self.app = Flask(