diff --git a/libraries/AP_GPS/AP_GPS_UBLOX.cpp b/libraries/AP_GPS/AP_GPS_UBLOX.cpp
index 82ab572777..b2af246d1c 100644
--- a/libraries/AP_GPS/AP_GPS_UBLOX.cpp
+++ b/libraries/AP_GPS/AP_GPS_UBLOX.cpp
@@ -60,6 +60,7 @@ AP_GPS_UBLOX::AP_GPS_UBLOX(AP_GPS &_gps, AP_GPS::GPS_State &_state, AP_HAL::UART
     _disable_counter(0),
     next_fix(AP_GPS::NO_FIX),
     rate_update_step(0),
+    _last_5hz_time(0),
     _last_hw_status(0)
 {
     // stop any config strings that are pending