diff --git a/libraries/AP_ADSB/AP_ADSB.cpp b/libraries/AP_ADSB/AP_ADSB.cpp
index a36a1849b2..53ba4291dc 100644
--- a/libraries/AP_ADSB/AP_ADSB.cpp
+++ b/libraries/AP_ADSB/AP_ADSB.cpp
@@ -37,7 +37,7 @@
 #include <AP_Logger/AP_Logger.h>
 #include <AP_Vehicle/AP_Vehicle_Type.h>
 #include <GCS_MAVLink/GCS.h>
-
+#include <AP_RTC/AP_RTC.h>
 
 #define VEHICLE_TIMEOUT_MS              5000   // if no updates in this time, drop it from the list
 #define ADSB_SQUAWK_OCTAL_DEFAULT       1200