diff --git a/InnerDetector/InDetExample/InDetRecExample/python/TrackingCommon.py b/InnerDetector/InDetExample/InDetRecExample/python/TrackingCommon.py
index 761913acf116c19969b1f994c19b59084829ef5d..1512c01c43b28e5e753f5b0d082193c059730c30 100644
--- a/InnerDetector/InDetExample/InDetRecExample/python/TrackingCommon.py
+++ b/InnerDetector/InDetExample/InDetRecExample/python/TrackingCommon.py
@@ -325,6 +325,10 @@ def getNnClusterizationFactory(name='NnClusterizationFactory', **kwargs) :
     useTTrainedNetworks = InDetFlags.useNNTTrainedNetworks()
     from AtlasGeoModel.CommonGMJobProperties import CommonGeometryFlags as geoFlags
     do_runI = geoFlags.Run() not in ["RUN2", "RUN3"]
+
+    if do_runI and not useTTrainedNetworks:
+      log.debug("useNNTTrainedNetworks must be True for Run I. Contact CTIDE for questions.")
+      useTTrainedNetworks = True
     
     if useTTrainedNetworks :
       log.debug("Setting up TTrainedNetworks")