diff --git a/conf/firmwares/rotorcraft.makefile b/conf/firmwares/rotorcraft.makefile
index bc6345b920..c9ef6eee63 100644
--- a/conf/firmwares/rotorcraft.makefile
+++ b/conf/firmwares/rotorcraft.makefile
@@ -40,6 +40,8 @@ ROTORCRAFT_INC = -I$(SRC_FIRMWARE) -I$(SRC_BOARD)
 
 ap.ARCHDIR = $(ARCH)
 
+# would be better to auto-generate this
+$(TARGET).CFLAGS 	+= -DFIRMWARE=ROTORCRAFT
 
 ap.CFLAGS += $(ROTORCRAFT_INC)
 ap.CFLAGS += -DBOARD_CONFIG=$(BOARD_CFG) -DPERIPHERALS_AUTO_INIT
diff --git a/conf/firmwares/subsystems/fixedwing/autopilot.makefile b/conf/firmwares/subsystems/fixedwing/autopilot.makefile
index c71127cf86..aeb82009a9 100644
--- a/conf/firmwares/subsystems/fixedwing/autopilot.makefile
+++ b/conf/firmwares/subsystems/fixedwing/autopilot.makefile
@@ -39,6 +39,9 @@ $(TARGET).CFLAGS 	+= -DBOARD_CONFIG=$(BOARD_CFG)
 $(TARGET).CFLAGS 	+= -DPERIPHERALS_AUTO_INIT
 $(TARGET).CFLAGS 	+= $(FIXEDWING_INC)
 
+# would be better to auto-generate this
+$(TARGET).CFLAGS 	+= -DFIRMWARE=FIXEDWING
+
 $(TARGET).srcs 	+= mcu.c
 $(TARGET).srcs 	+= $(SRC_ARCH)/mcu_arch.c
 
diff --git a/sw/airborne/modules/gps/gps_ubx_ucenter.c b/sw/airborne/modules/gps/gps_ubx_ucenter.c
index 1688915b47..34a11fec1b 100644
--- a/sw/airborne/modules/gps/gps_ubx_ucenter.c
+++ b/sw/airborne/modules/gps/gps_ubx_ucenter.c
@@ -379,7 +379,11 @@ static bool_t gps_ubx_ucenter_configure(uint8_t nr)
     gps_ubx_ucenter_enable_msg(UBX_NAV_ID, UBX_NAV_SVINFO_ID, 4);
     break;
   case 11:
+#if defined FIRMWARE && FIRMWARE == ROTORCRAFT
+    gps_ubx_ucenter_enable_msg(UBX_NAV_ID, UBX_NAV_SOL_ID, 1);
+#else
     gps_ubx_ucenter_enable_msg(UBX_NAV_ID, UBX_NAV_SOL_ID, 8);
+#endif
     break;
   case 12:
     // Disable UTM on old Lea4P