diff --git a/libraries/AP_Common/Location.cpp b/libraries/AP_Common/Location.cpp
index 6594c95623..bc537dab99 100644
--- a/libraries/AP_Common/Location.cpp
+++ b/libraries/AP_Common/Location.cpp
@@ -236,7 +236,7 @@ bool Location::get_vector_from_origin_NEU(Vector3f &vec_neu) const
     return true;
 }
 
-// return distance in meters between two locations
+// return horizontal distance in meters between two locations
 ftype Location::get_distance(const struct Location &loc2) const
 {
     ftype dlat = (ftype)(loc2.lat - lat);
diff --git a/libraries/AP_Common/Location.h b/libraries/AP_Common/Location.h
index e444b6b22a..3b61215ac3 100644
--- a/libraries/AP_Common/Location.h
+++ b/libraries/AP_Common/Location.h
@@ -56,7 +56,7 @@ public:
     bool get_vector_xy_from_origin_NE(Vector2f &vec_ne) const WARN_IF_UNUSED;
     bool get_vector_from_origin_NEU(Vector3f &vec_neu) const WARN_IF_UNUSED;
 
-    // return distance in meters between two locations
+    // return horizontal distance in meters between two locations
     ftype get_distance(const struct Location &loc2) const;
 
     // return the altitude difference in meters taking into account alt frame.