diff --git a/sw/airborne/arch/lpc21/subsystems/radio_control/ppm_arch.h b/sw/airborne/arch/lpc21/subsystems/radio_control/ppm_arch.h
index b06954aa48..b42eefcd95 100644
--- a/sw/airborne/arch/lpc21/subsystems/radio_control/ppm_arch.h
+++ b/sw/airborne/arch/lpc21/subsystems/radio_control/ppm_arch.h
@@ -28,6 +28,8 @@
 #include "LPC21xx.h"
 #include BOARD_CONFIG
 
+#include "mcu_periph/sys_time.h"
+
 /**
  * On tiny (and booz) the ppm counter is running at the same speed as
  * the systic counter. There is no reason for this to be true.
diff --git a/sw/airborne/arch/stm32/subsystems/radio_control/ppm_arch.h b/sw/airborne/arch/stm32/subsystems/radio_control/ppm_arch.h
index f1be912ecd..c3eebdec23 100644
--- a/sw/airborne/arch/stm32/subsystems/radio_control/ppm_arch.h
+++ b/sw/airborne/arch/stm32/subsystems/radio_control/ppm_arch.h
@@ -29,6 +29,8 @@
 #ifndef PPM_ARCH_H
 #define PPM_ARCH_H
 
+#include "mcu_periph/sys_time.h"
+
 /**
  * On tiny (and booz) the ppm counter is running at the same speed as
  * the systic counter. There is no reason for this to be true.
diff --git a/sw/airborne/boards/booz_1.0.h b/sw/airborne/boards/booz_1.0.h
index 2d6d2a5b8a..95048428e7 100644
--- a/sw/airborne/boards/booz_1.0.h
+++ b/sw/airborne/boards/booz_1.0.h
@@ -142,7 +142,7 @@
 #define PWM1_PINSEL_BIT 14
 
 
-#define BOARD_HAS_BARO
+#define BOARD_HAS_BARO 1
 
 /*
  * Modem
diff --git a/sw/airborne/boards/lisa_l_1.0.h b/sw/airborne/boards/lisa_l_1.0.h
index 5cf7ef8e27..f593587a10 100644
--- a/sw/airborne/boards/lisa_l_1.0.h
+++ b/sw/airborne/boards/lisa_l_1.0.h
@@ -37,6 +37,6 @@
 #define BOARD_ADC_CHANNEL_3 ADC_Channel_0
 #define BOARD_ADC_CHANNEL_4 ADC_Channel_15
 
-#define BOARD_HAS_BARO
+#define BOARD_HAS_BARO 1
 
 #endif /* CONFIG_LISA_L_1_0_H */
diff --git a/sw/airborne/boards/lisa_m_1.0.h b/sw/airborne/boards/lisa_m_1.0.h
index 65c50d754d..9ef15ac72b 100644
--- a/sw/airborne/boards/lisa_m_1.0.h
+++ b/sw/airborne/boards/lisa_m_1.0.h
@@ -54,7 +54,7 @@
 #define BOARD_ADC_CHANNEL_3 ADC_Channel_14
 #define BOARD_ADC_CHANNEL_4 ADC_Channel_11
 
-#define BOARD_HAS_BARO
+#define BOARD_HAS_BARO 1
 
 #define USE_OPENCM3 1
 
diff --git a/sw/airborne/boards/navgo_1.0.h b/sw/airborne/boards/navgo_1.0.h
index 17a6fbf118..0f23fa9ee0 100644
--- a/sw/airborne/boards/navgo_1.0.h
+++ b/sw/airborne/boards/navgo_1.0.h
@@ -76,6 +76,6 @@
 #define PWM1_PINSEL_VAL 0x02
 #define PWM1_PINSEL_BIT 14
 
-#define BOARD_HAS_BARO
+#define BOARD_HAS_BARO 1
 
 #endif /* CONFIG_NAVGO_V1_0_H */
diff --git a/sw/airborne/boards/umarim_1.0.h b/sw/airborne/boards/umarim_1.0.h
index eb47a0545c..6c0b01187c 100644
--- a/sw/airborne/boards/umarim_1.0.h
+++ b/sw/airborne/boards/umarim_1.0.h
@@ -99,6 +99,6 @@
 #define SPI1_DRDY_EINT         0
 #define SPI1_DRDY_VIC_IT       VIC_EINT0
 
-#define BOARD_HAS_BARO
+#define BOARD_HAS_BARO 1
 
 #endif /* CONFIG_UMARIM_V1_0_H */
diff --git a/sw/airborne/firmwares/fixedwing/ap_downlink.h b/sw/airborne/firmwares/fixedwing/ap_downlink.h
index 30dee8aec7..08e80ea45f 100644
--- a/sw/airborne/firmwares/fixedwing/ap_downlink.h
+++ b/sw/airborne/firmwares/fixedwing/ap_downlink.h
@@ -245,7 +245,9 @@ extern uint8_t telemetry_mode_Ap_DefaultChannel;
 #define PERIODIC_SEND_SCP_STATUS(_trans, _dev) {}
 #endif
 
-#ifdef BOARD_HAS_BARO
+//FIXME: we need a better switch here...
+#if BOARD_HAS_BARO && USE_BARO_AS_ALTIMETER
+#include "subsystems/sensors/baro.h"
 #define PERIODIC_SEND_BARO_RAW(_trans, _dev) {  \
     DOWNLINK_SEND_BARO_RAW(_trans, _dev,        \
                            &baro.absolute,      \
diff --git a/sw/airborne/firmwares/fixedwing/main_ap.c b/sw/airborne/firmwares/fixedwing/main_ap.c
index f5d76ff2a5..787d6c59e0 100644
--- a/sw/airborne/firmwares/fixedwing/main_ap.c
+++ b/sw/airborne/firmwares/fixedwing/main_ap.c
@@ -69,7 +69,7 @@
 #include "subsystems/datalink/datalink.h"
 #include "subsystems/settings.h"
 #include "subsystems/datalink/xbee.h"
-#include "ap_downlink.h"
+#include "firmwares/fixedwing/ap_downlink.h"
 
 // modules & settings
 #include "generated/modules.h"
diff --git a/sw/airborne/subsystems/imu/imu_b2.h b/sw/airborne/subsystems/imu/imu_b2.h
index 1860501be9..02b7e69c59 100644
--- a/sw/airborne/subsystems/imu/imu_b2.h
+++ b/sw/airborne/subsystems/imu/imu_b2.h
@@ -169,7 +169,7 @@
     }									\
   }
 #elif defined IMU_B2_MAG_TYPE && IMU_B2_MAG_TYPE == IMU_B2_MAG_HMC5843
-include "peripherals/hmc5843.h"
+#include "peripherals/hmc5843.h"
 #define foo_handler() {}
 #define ImuMagEvent(_mag_handler) {					\
     MagEvent(foo_handler);                          \