--- a/src/wifi/model/wifi-phy.h	Mon Nov 28 23:45:36 2016 +0100
+++ b/src/wifi/model/wifi-phy.h	Tue Nov 29 23:16:51 2016 +0100
@@ -1399,7 +1399,7 @@
    *
    * \return the mobility model this PHY is associated with
    */
-  Ptr<MobilityModel> GetMobility (void);
+  Ptr<MobilityModel> GetMobility (void) const;
 
   /**
    * \param freq the operating center frequency (MHz) on this node.