diff --git a/conf/firmwares/subsystems/fixedwing/ins_gps_passthrough.makefile b/conf/firmwares/subsystems/fixedwing/ins_gps_passthrough.makefile
index f6f1c628f9..0ab3fc9cca 100644
--- a/conf/firmwares/subsystems/fixedwing/ins_gps_passthrough.makefile
+++ b/conf/firmwares/subsystems/fixedwing/ins_gps_passthrough.makefile
@@ -1,6 +1,14 @@
+# Hey Emacs, this is a -*- makefile -*-
 
-ap.srcs   += $(SRC_SUBSYSTEMS)/ins/ins_gps_passthrough.c
+ins_srcs   += $(SRC_SUBSYSTEMS)/ins.c
+ins_srcs   += $(SRC_SUBSYSTEMS)/ins/ins_gps_passthrough.c
 
-sim.srcs  += $(SRC_SUBSYSTEMS)/ins/ins_gps_passthrough.c
 
-nps.srcs  += $(SRC_SUBSYSTEMS)/ins/ins_gps_passthrough.c
+ap.CFLAGS += $(ins_CFLAGS)
+ap.srcs   += $(ins_srcs)
+
+sim.CFLAGS += $(ins_CFLAGS)
+sim.srcs   += $(ins_srcs)
+
+nps.CFLAGS += $(ins_CFLAGS)
+nps.srcs   += $(ins_srcs)
diff --git a/conf/firmwares/subsystems/fixedwing/ins_xsens.makefile b/conf/firmwares/subsystems/fixedwing/ins_xsens.makefile
index 4440f92bfd..b9589d04c5 100644
--- a/conf/firmwares/subsystems/fixedwing/ins_xsens.makefile
+++ b/conf/firmwares/subsystems/fixedwing/ins_xsens.makefile
@@ -28,6 +28,7 @@ ap.CFLAGS += -DUSE_UART$(XSENS_UART_NR)
 ap.CFLAGS += -DINS_LINK=UART$(XSENS_UART_NR)
 ap.CFLAGS += -DUART$(XSENS_UART_NR)_BAUD=$(XSENS_UART_BAUD)
 ap.CFLAGS += -DXSENS_OUTPUT_MODE=0x1836
+ap.srcs   += $(SRC_SUBSYSTEMS)/ins.c
 ap.srcs   += $(SRC_MODULES)/ins/ins_xsens.c
 ap.CFLAGS += -DAHRS_TRIGGERED_ATTITUDE_LOOP
 
@@ -56,6 +57,7 @@ $(TARGET).CFLAGS += -DUSE_AHRS -DAHRS_UPDATE_FW_ESTIMATOR
 $(TARGET).srcs   += $(SRC_SUBSYSTEMS)/ahrs.c
 $(TARGET).srcs   += $(SRC_SUBSYSTEMS)/ahrs/ahrs_sim.c
 
+$(TARGET).srcs   += $(SRC_SUBSYSTEMS)/ins.c
 $(TARGET).srcs   += $(SRC_SUBSYSTEMS)/ins/ins_gps_passthrough.c
 
 $(TARGET).CFLAGS += -DUSE_GPS -DGPS_USE_LATLONG
diff --git a/conf/firmwares/subsystems/fixedwing/ins_xsens700.makefile b/conf/firmwares/subsystems/fixedwing/ins_xsens700.makefile
index a28dbe30dc..eb064c36a9 100644
--- a/conf/firmwares/subsystems/fixedwing/ins_xsens700.makefile
+++ b/conf/firmwares/subsystems/fixedwing/ins_xsens700.makefile
@@ -50,9 +50,8 @@ else
 ap.CFLAGS += -DUART$(XSENS_UART_NR)_BAUD=B230400
 endif
 
-ap.CFLAGS += -DUSE_GPS_XSENS
-ap.CFLAGS += -DGPS_NB_CHANNELS=50
 ap.CFLAGS += -DXSENS_OUTPUT_MODE=0x1836
+ap.srcs   += $(SRC_SUBSYSTEMS)/ins.c
 ap.srcs   += $(SRC_MODULES)/ins/ins_xsens700.c
 ap.CFLAGS += -DAHRS_TRIGGERED_ATTITUDE_LOOP
 
@@ -68,28 +67,34 @@ fbw.CFLAGS += -DAHRS_TYPE_H=\"modules/ins/ins_xsens.h\"
 endif
 
 
-ifeq ($(TARGET), sim)
-
-sim.CFLAGS += -DAHRS_TYPE_H=\"subsystems/ahrs/ahrs_sim.h\"
-sim.CFLAGS += -DUSE_AHRS -DAHRS_UPDATE_FW_ESTIMATOR
-
-sim.srcs   += $(SRC_SUBSYSTEMS)/ahrs.c
-sim.srcs   += $(SRC_SUBSYSTEMS)/ahrs/ahrs_sim.c
-
-endif
-
 #########################################
 ## GPS
 
 # ap.CFLAGS += -DGPS
+ap.CFLAGS += -DUSE_GPS_XSENS
+ap.CFLAGS += -DGPS_NB_CHANNELS=50
+ap.srcs += $(SRC_SUBSYSTEMS)/gps.c
 
+
+#########################################
+## Simulator
+SIM_TARGETS = sim jsbsim nps
+
+ifneq (,$(findstring $(TARGET),$(SIM_TARGETS)))
+
+$(TARGET).CFLAGS += -DAHRS_TYPE_H=\"subsystems/ahrs/ahrs_sim.h\"
+$(TARGET).CFLAGS += -DUSE_AHRS -DAHRS_UPDATE_FW_ESTIMATOR
+
+$(TARGET).srcs   += $(SRC_SUBSYSTEMS)/ahrs.c
+$(TARGET).srcs   += $(SRC_SUBSYSTEMS)/ahrs/ahrs_sim.c
+
+$(TARGET).srcs   += $(SRC_SUBSYSTEMS)/ins.c
+$(TARGET).srcs   += $(SRC_SUBSYSTEMS)/ins/ins_gps_passthrough.c
+
+$(TARGET).CFLAGS += -DUSE_GPS -DGPS_USE_LATLONG
+$(TARGET).CFLAGS += -DGPS_TYPE_H=\"subsystems/gps/gps_sim.h\"
+$(TARGET).srcs += $(SRC_SUBSYSTEMS)/gps/gps_sim.c
 $(TARGET).srcs += $(SRC_SUBSYSTEMS)/gps.c
 
-sim.CFLAGS += -DUSE_GPS -DGPS_USE_LATLONG
-sim.CFLAGS += -DGPS_TYPE_H=\"subsystems/gps/gps_sim.h\"
-sim.srcs += $(SRC_SUBSYSTEMS)/gps/gps_sim.c
-
-
-
-
+endif