diff --git a/libraries/AP_GPS/AP_GPS.cpp b/libraries/AP_GPS/AP_GPS.cpp
index 66f2dbba06..476c4e9628 100644
--- a/libraries/AP_GPS/AP_GPS.cpp
+++ b/libraries/AP_GPS/AP_GPS.cpp
@@ -134,7 +134,7 @@ const AP_Param::GroupInfo AP_GPS::var_info[] = {
     // @Description: Masked with the SBP msg_type field to determine whether SBR1/SBR2 data is logged
     // @Values: 0:None (0x0000),-1:All (0xFFFF),-256:External only (0xFF00)
     // @User: Advanced
-    AP_GROUPINFO("SBP_LOGMASK", 8, AP_GPS, _sbp_logmask, 0xFF00),
+    AP_GROUPINFO("SBP_LOGMASK", 8, AP_GPS, _sbp_logmask, -256),
 
     // @Param: RAW_DATA
     // @DisplayName: Raw data logging