diff --git a/webservice/serve_overview.py b/webservice/serve_overview.py
index 1e445cf70ef642d42468280dfda8102a74665016..66db91879d2d6a8f267066d6207c7e6d7607d8bb 100644
--- a/webservice/serve_overview.py
+++ b/webservice/serve_overview.py
@@ -250,7 +250,7 @@ class RequestHandler(BaseHTTPRequestHandler):
             tsize = 0
             for run in runs:
                 run = int(run)
-                if detector not in cal_config['data-mapping']:
+                if 'karabo-da' not in cal_config['data-mapping'].get(detector, {}):
                     continue
                 # ToDo calculate tsize based on selected karabo-da
                 for mp in cal_config['data-mapping'][detector]['karabo-da']: