diff --git a/conf/firmwares/subsystems/fixedwing/ahrs_float_cmpl_rmat.makefile b/conf/firmwares/subsystems/fixedwing/ahrs_float_cmpl_rmat.makefile
index fa70116214..6d82542b6c 100644
--- a/conf/firmwares/subsystems/fixedwing/ahrs_float_cmpl_rmat.makefile
+++ b/conf/firmwares/subsystems/fixedwing/ahrs_float_cmpl_rmat.makefile
@@ -27,6 +27,9 @@ AHRS_SRCS   += subsystems/ahrs/ahrs_aligner.c
 ap.CFLAGS += $(AHRS_CFLAGS)
 ap.srcs += $(AHRS_SRCS)
 
+#
+# NPS uses the real algorithm
+#
 nps.CFLAGS += $(AHRS_CFLAGS)
 nps.srcs += $(AHRS_SRCS)
 
diff --git a/conf/firmwares/subsystems/fixedwing/ahrs_float_dcm.makefile b/conf/firmwares/subsystems/fixedwing/ahrs_float_dcm.makefile
index 0223edbc82..6427993c02 100644
--- a/conf/firmwares/subsystems/fixedwing/ahrs_float_dcm.makefile
+++ b/conf/firmwares/subsystems/fixedwing/ahrs_float_dcm.makefile
@@ -25,10 +25,12 @@ endif
 ap.CFLAGS += $(AHRS_CFLAGS)
 ap.srcs += $(AHRS_SRCS)
 
+#
+# NPS uses the real algorithm
+#
 nps.CFLAGS += $(AHRS_CFLAGS)
 nps.srcs += $(AHRS_SRCS)
 
-
 #
 # Simple simulation of the AHRS result
 #
diff --git a/conf/firmwares/subsystems/fixedwing/ahrs_int_cmpl_quat.makefile b/conf/firmwares/subsystems/fixedwing/ahrs_int_cmpl_quat.makefile
index ca4c99ecdb..5bea385eaa 100644
--- a/conf/firmwares/subsystems/fixedwing/ahrs_int_cmpl_quat.makefile
+++ b/conf/firmwares/subsystems/fixedwing/ahrs_int_cmpl_quat.makefile
@@ -36,6 +36,11 @@ ap.srcs += $(AHRS_SRCS)
 #ap.CFLAGS += -DAHRS_CORRECT_FREQUENCY=$(AHRS_CORRECT_FREQUENCY)
 #endif
 
+#
+# NPS uses the real algorithm
+#
+nps.CFLAGS += $(AHRS_CFLAGS)
+nps.srcs += $(AHRS_SRCS)
 
 #
 # Simple simulation of the AHRS result
diff --git a/conf/firmwares/subsystems/shared/imu_nps.makefile b/conf/firmwares/subsystems/shared/imu_nps.makefile
index e26d035cd4..a84003b6d6 100644
--- a/conf/firmwares/subsystems/shared/imu_nps.makefile
+++ b/conf/firmwares/subsystems/shared/imu_nps.makefile
@@ -20,5 +20,5 @@
 #  </section>
 #
 
-nps.CFLAGS += -DIMU_TYPE_H=\"imu/imu_nps.h\"
+nps.CFLAGS += -DIMU_TYPE_H=\"imu/imu_nps.h\" -DUSE_IMU
 nps.srcs   += $(SRC_SUBSYSTEMS)/imu.c $(SRC_SUBSYSTEMS)/imu/imu_nps.c