diff --git a/flight/modules/GPS/DJI.c b/flight/modules/GPS/DJI.c
index f12c34ffb..a02e8301c 100644
--- a/flight/modules/GPS/DJI.c
+++ b/flight/modules/GPS/DJI.c
@@ -290,16 +290,15 @@ static void parse_dji_gps(struct DJIPacket *dji, GPSPositionSensorData *gpsPosit
     }
     gpsPosition->SensorType = GPSPOSITIONSENSOR_SENSORTYPE_DJI;
     gpsPosition->AutoConfigStatus = GPSPOSITIONSENSOR_AUTOCONFIGSTATUS_DISABLED;
-    // gpsPosition->BaudRate = GPSPOSITIONSENSOR_BAUDRATE_115200;
     GPSPositionSensorSet(gpsPosition);
 
 #if !defined(PIOS_GPS_MINIMAL)
     // Time is valid, set GpsTime
     GPSTimeData gpsTime;
-    // the lowest bit of day and the highest bit of hour overlap (xored? no stranger than that)
+    // the lowest bit of day and the highest bit of hour overlap (xored? no, stranger than that)
     // this causes strange day/hour changes
     // we could track it here and even if we guess wrong initially
-    // we can massage the data so that time doesn't jump
+    // we can massage the data so that time doesn't jump at least
     // and maybe make the assumption that most people will fly at 5pm, not 1am
     // this is part of the DJI protocol
     // see DJI.h for further info
diff --git a/flight/modules/GPS/GPS.c b/flight/modules/GPS/GPS.c
index 4bf899378..04a38f8f4 100644
--- a/flight/modules/GPS/GPS.c
+++ b/flight/modules/GPS/GPS.c
@@ -61,10 +61,14 @@ PERF_DEFINE_COUNTER(counterBytesIn);
 PERF_DEFINE_COUNTER(counterRate);
 PERF_DEFINE_COUNTER(counterParse);
 
+#if defined(ANY_GPS_PARSER) || defined(ANY_FULL_GPS_PARSER) || defined(ANY_FULL_MAG_PARSER)
+#error ANY_GPS_PARSER ANY_FULL_GPS_PARSER and ANY_FULL_MAG_PARSER should all be undefined at this point.
+#endif
+
 #if defined(PIOS_INCLUDE_GPS_NMEA_PARSER) || defined(PIOS_INCLUDE_GPS_UBX_PARSER) || defined(PIOS_INCLUDE_GPS_DJI_PARSER)
 #define ANY_GPS_PARSER
 #endif
-#if (defined(ANY_GPS_PARSER)) && !defined(PIOS_GPS_MINIMAL)
+#if defined(ANY_GPS_PARSER) && !defined(PIOS_GPS_MINIMAL)
 #define ANY_FULL_GPS_PARSER
 #endif
 #if (defined(PIOS_INCLUDE_HMC5X83) || defined(PIOS_INCLUDE_GPS_UBX_PARSER) || defined(PIOS_INCLUDE_GPS_DJI_PARSER)) && !defined(PIOS_GPS_MINIMAL)