diff --git a/src/gravity_properties.h b/src/gravity_properties.h
index 4f0c5433b672d21e9a666e68a7253d246d87c7e7..2c862b5aa08da9707c855136d4b7771e3e719f09 100644
--- a/src/gravity_properties.h
+++ b/src/gravity_properties.h
@@ -57,7 +57,7 @@ struct gravity_props {
   /*! What MAC are we currently using? */
   int use_advanced_mac;
 
-  /*! Are we using the adaptive opening angle? */
+  /*! Are we using the adaptive opening angle? (as read from param file) */
   int use_adaptive_tolerance;
 
   /*! Accuracy parameter of the advanced MAC */