diff --git a/conf/firmwares/subsystems/rotorcraft/fdm_jsbsim.makefile b/conf/firmwares/subsystems/rotorcraft/fdm_jsbsim.makefile
index 03c68288a4..28d76e543f 100644
--- a/conf/firmwares/subsystems/rotorcraft/fdm_jsbsim.makefile
+++ b/conf/firmwares/subsystems/rotorcraft/fdm_jsbsim.makefile
@@ -154,20 +154,17 @@ endif
 nps.CFLAGS += -DUSE_NAVIGATION
 nps.srcs += $(SRC_FIRMWARE)/guidance/guidance_h.c
 nps.srcs += $(SRC_FIRMWARE)/guidance/guidance_v.c
-nps.srcs += $(SRC_SUBSYSTEMS)/ins.c
-
-#  vertical filter float version
-nps.srcs += $(SRC_SUBSYSTEMS)/ins/vf_float.c
-nps.CFLAGS += -DUSE_VFF -DDT_VFILTER='(1./512.)'
 
 #
 # INS choice
 #
-# include ins_hff.makefile
+# include subsystems/rotorcraft/ins.makefile
 # or
-# nothing
+# include subsystems/rotorcraft/ins_extended.makefile
+#
+# extra:
+# include subsystems/rotorcraft/ins_hff.makefile
 #
-
 
 nps.srcs += $(SRC_FIRMWARE)/navigation.c
 nps.srcs += $(SRC_SUBSYSTEMS)/navigation/common_flight_plan.c
diff --git a/conf/firmwares/subsystems/rotorcraft/ins.makefile b/conf/firmwares/subsystems/rotorcraft/ins.makefile
index 7fb608ffef..7340c078a2 100644
--- a/conf/firmwares/subsystems/rotorcraft/ins.makefile
+++ b/conf/firmwares/subsystems/rotorcraft/ins.makefile
@@ -2,9 +2,9 @@
 # simple INS with float vertical filter
 #
 
-ap.srcs += $(SRC_SUBSYSTEMS)/ins.c
+$(TARGET).srcs += $(SRC_SUBSYSTEMS)/ins.c
 
 #  vertical filter float version
-ap.srcs += $(SRC_SUBSYSTEMS)/ins/vf_float.c
-ap.CFLAGS += -DUSE_VFF -DDT_VFILTER='(1./$(PERIODIC_FREQUENCY).)'
+$(TARGET).srcs += $(SRC_SUBSYSTEMS)/ins/vf_float.c
+$(TARGET).CFLAGS += -DUSE_VFF -DDT_VFILTER='(1./$(PERIODIC_FREQUENCY).)'
 
diff --git a/conf/firmwares/subsystems/rotorcraft/ins_extended.makefile b/conf/firmwares/subsystems/rotorcraft/ins_extended.makefile
index f1cd021b44..e872ac1f77 100644
--- a/conf/firmwares/subsystems/rotorcraft/ins_extended.makefile
+++ b/conf/firmwares/subsystems/rotorcraft/ins_extended.makefile
@@ -2,9 +2,9 @@
 # extended INS with vertical filter using sonar in a better way (flap ground)
 #
 
-ap.srcs += $(SRC_SUBSYSTEMS)/ins_extended.c
+$(TARGET).srcs += $(SRC_SUBSYSTEMS)/ins_extended.c
 
 #  vertical filter float version
-ap.srcs += $(SRC_SUBSYSTEMS)/ins/vf_extended_float.c
-ap.CFLAGS += -DUSE_VFF_EXTENDED -DDT_VFILTER='(1./$(PERIODIC_FREQUENCY).)'
+$(TARGET).srcs += $(SRC_SUBSYSTEMS)/ins/vf_extended_float.c
+$(TARGET).CFLAGS += -DUSE_VFF_EXTENDED -DDT_VFILTER='(1./$(PERIODIC_FREQUENCY).)'