diff --git a/Tethering/apex/Android.bp b/Tethering/apex/Android.bp
index 8840394..565675f 100644
--- a/Tethering/apex/Android.bp
+++ b/Tethering/apex/Android.bp
@@ -50,6 +50,15 @@
 // as the above target may have different "enabled" values
 // depending on the branch
 
+// cronet_in_tethering_apex_defaults can be used to specify an apex_defaults target that either
+// enables or disables inclusion of Cronet in the Tethering apex. This is used to disable Cronet
+// on tm-mainline-prod. Note: in order for Cronet APIs to work Cronet must also be enabled
+// by the cronet_java_*_defaults in common/TetheringLib/Android.bp.
+cronet_in_tethering_apex_defaults = "CronetInTetheringApexDefaultsEnabled"
+// This is a placeholder comment to avoid merge conflicts
+// as cronet_apex_defaults may have different values
+// depending on the branch
+
 apex {
     name: "com.android.tethering",
     defaults: [