diff --git a/conf/autopilot/subsystems/fixedwing/ahrs_float_dcm.makefile b/conf/autopilot/subsystems/fixedwing/ahrs_float_dcm.makefile
index 70f8f745e8c..8020cc652a0 100644
--- a/conf/autopilot/subsystems/fixedwing/ahrs_float_dcm.makefile
+++ b/conf/autopilot/subsystems/fixedwing/ahrs_float_dcm.makefile
@@ -4,6 +4,7 @@
 
 
 $(TARGET).CFLAGS += -DAHRS_TYPE_H=\"subsystems/ahrs/ahrs_float_dcm.h\"
+$(TARGET).CFLAGS += -DUSE_AHRS_ALIGNER
 
 ifeq ($(TARGET), ap)
 
diff --git a/conf/autopilot/subsystems/fixedwing/ahrs_int_cmpl_euler.makefile b/conf/autopilot/subsystems/fixedwing/ahrs_int_cmpl_euler.makefile
index 75e0d2d75f2..d66dd0183cf 100644
--- a/conf/autopilot/subsystems/fixedwing/ahrs_int_cmpl_euler.makefile
+++ b/conf/autopilot/subsystems/fixedwing/ahrs_int_cmpl_euler.makefile
@@ -4,6 +4,8 @@
 #
 
 AHRS_CFLAGS  = -DUSE_AHRS -DAHRS_UPDATE_FW_ESTIMATOR -DUSE_AHRS_CMPL
+AHRS_CFLAGS += -DUSE_AHRS_ALIGNER
+
 ifdef AHRS_ALIGNER_LED
 AHRS_CFLAGS += -DAHRS_ALIGNER_LED=$(AHRS_ALIGNER_LED)
 endif
diff --git a/conf/autopilot/subsystems/fixedwing/ahrs_int_cmpl_quat.makefile b/conf/autopilot/subsystems/fixedwing/ahrs_int_cmpl_quat.makefile
index 369d174cafe..7f2ef856954 100644
--- a/conf/autopilot/subsystems/fixedwing/ahrs_int_cmpl_quat.makefile
+++ b/conf/autopilot/subsystems/fixedwing/ahrs_int_cmpl_quat.makefile
@@ -7,6 +7,8 @@
 #
 
 AHRS_CFLAGS  = -DUSE_AHRS -DAHRS_UPDATE_FW_ESTIMATOR
+AHRS_CFLAGS += -DUSE_AHRS_ALIGNER
+
 ifdef AHRS_ALIGNER_LED
 AHRS_CFLAGS += -DAHRS_ALIGNER_LED=$(AHRS_ALIGNER_LED)
 endif
diff --git a/conf/autopilot/subsystems/rotorcraft/ahrs_int_cmpl_euler.makefile b/conf/autopilot/subsystems/rotorcraft/ahrs_int_cmpl_euler.makefile
index 457f08f5752..ae74dc22a82 100644
--- a/conf/autopilot/subsystems/rotorcraft/ahrs_int_cmpl_euler.makefile
+++ b/conf/autopilot/subsystems/rotorcraft/ahrs_int_cmpl_euler.makefile
@@ -1,16 +1,15 @@
+# Hey Emacs, this is a -*- makefile -*-
 #
 # Fixed point complementary filter using euler angles for attitude estimation
 #
 
+AHRS_CFLAGS  = -DUSE_AHRS -DUSE_AHRS_CMPL
+AHRS_CFLAGS += -DUSE_AHRS_ALIGNER
 ifdef AHRS_ALIGNER_LED
-ap.CFLAGS += -DAHRS_ALIGNER_LED=$(AHRS_ALIGNER_LED)
+AHRS_CFLAGS += -DAHRS_ALIGNER_LED=$(AHRS_ALIGNER_LED)
 endif
-ap.CFLAGS += -DUSE_AHRS_CMPL
-ap.srcs += $(SRC_SUBSYSTEMS)/ahrs.c
-ap.srcs += $(SRC_SUBSYSTEMS)/ahrs/ahrs_aligner.c
-ap.srcs += $(SRC_SUBSYSTEMS)/ahrs/ahrs_int_cmpl_euler.c
+AHRS_CFLAGS += -DAHRS_TYPE_H=\"subsystems/ahrs/ahrs_int_cmpl_euler.h\"
+AHRS_SRCS   += subsystems/ahrs.c
+AHRS_SRCS   += subsystems/ahrs/ahrs_int_cmpl_euler.c
+AHRS_SRCS   += subsystems/ahrs/ahrs_aligner.c
 
-sim.CFLAGS += -DUSE_AHRS_CMPL -DAHRS_ALIGNER_LED=3
-sim.srcs += $(SRC_SUBSYSTEMS)/ahrs.c
-sim.srcs += $(SRC_SUBSYSTEMS)/ahrs/ahrs_aligner.c
-sim.srcs += $(SRC_SUBSYSTEMS)/ahrs/ahrs_int_cmpl_euler.c
diff --git a/conf/autopilot/subsystems/rotorcraft/ahrs_int_cmpl_quat.makefile b/conf/autopilot/subsystems/rotorcraft/ahrs_int_cmpl_quat.makefile
index b42b2e03704..25386fd6271 100644
--- a/conf/autopilot/subsystems/rotorcraft/ahrs_int_cmpl_quat.makefile
+++ b/conf/autopilot/subsystems/rotorcraft/ahrs_int_cmpl_quat.makefile
@@ -7,6 +7,7 @@
 #
 
 AHRS_CFLAGS  = -DUSE_AHRS
+AHRS_CFLAGS += -DUSE_AHRS_ALIGNER
 ifdef AHRS_ALIGNER_LED
 AHRS_CFLAGS += -DAHRS_ALIGNER_LED=$(AHRS_ALIGNER_LED)
 endif