diff --git a/modules/features/teamsbot/routeFeatureTeamsbot.py b/modules/features/teamsbot/routeFeatureTeamsbot.py
index 997b9a58..14ccfa18 100644
--- a/modules/features/teamsbot/routeFeatureTeamsbot.py
+++ b/modules/features/teamsbot/routeFeatureTeamsbot.py
@@ -122,9 +122,11 @@ async def startSession(
     createdSession = interface.createSession(sessionData)
     sessionId = createdSession.get("id")
     
-    # Derive gateway base URL from the incoming request so the bridge
-    # can build full callback/WS URLs targeting this specific gateway instance.
-    gatewayBaseUrl = str(request.base_url).rstrip("/")
+    # Use APP_API_URL from global config for the gateway base URL
+    # request.base_url can be http:// behind a reverse proxy even when client uses https://
+    from modules.shared.configuration import APP_CONFIG
+    appApiUrl = APP_CONFIG.get("APP_API_URL", "")
+    gatewayBaseUrl = appApiUrl.rstrip("/") if appApiUrl else str(request.base_url).rstrip("/")
     
     # Start the bot in background (join meeting via bridge)
     service = TeamsbotService(context.user, mandateId, instanceId, config)