diff --git a/Tools/Replay/Replay.pde b/Tools/Replay/Replay.pde
index 8e95c26263..3856346785 100644
--- a/Tools/Replay/Replay.pde
+++ b/Tools/Replay/Replay.pde
@@ -43,6 +43,7 @@
 #include <AP_InertialNav.h>
 #include <AP_NavEKF.h>
 #include <AP_Mission.h>
+#include <AP_Terrain.h>
 #include <Parameters.h>
 #include <stdio.h>
 #include <getopt.h>