diff --git a/libraries/AP_GPS/AP_GPS.cpp b/libraries/AP_GPS/AP_GPS.cpp
index ab055f2ff7..33344559a7 100644
--- a/libraries/AP_GPS/AP_GPS.cpp
+++ b/libraries/AP_GPS/AP_GPS.cpp
@@ -206,7 +206,7 @@ AP_GPS::detect_instance(uint8_t instance)
     if (now - dstate->last_baud_change_ms > 1200) {
         // try the next baud rate
 		dstate->last_baud++;
-		if (dstate->last_baud == sizeof(_baudrates) / sizeof(_baudrates[0])) {
+		if (dstate->last_baud == ARRAY_SIZE(_baudrates)) {
 			dstate->last_baud = 0;
 		}
 		uint32_t baudrate = pgm_read_dword(&_baudrates[dstate->last_baud]);
diff --git a/libraries/AP_GPS/AP_GPS_SBP.cpp b/libraries/AP_GPS/AP_GPS_SBP.cpp
index c04feca5ca..f151128c56 100644
--- a/libraries/AP_GPS/AP_GPS_SBP.cpp
+++ b/libraries/AP_GPS/AP_GPS_SBP.cpp
@@ -451,7 +451,7 @@ AP_GPS_SBP::logging_write_headers(void)
 {
     if (!logging_started) {
         logging_started = true;
-        gps._DataFlash->AddLogFormats(sbp_log_structures, sizeof(sbp_log_structures) / sizeof(LogStructure));
+        gps._DataFlash->AddLogFormats(sbp_log_structures, ARRAY_SIZE(sbp_log_structures));
     }
 }