diff --git a/mk/px4_targets.mk b/mk/px4_targets.mk
index cb77a39aab..c227871178 100644
--- a/mk/px4_targets.mk
+++ b/mk/px4_targets.mk
@@ -43,6 +43,8 @@ EXTRAFLAGS += -DUAVCAN=1
 # Add missing parts from libc and libstdc++
 EXTRAFLAGS += -DHAVE_STD_NULLPTR_T=0
 
+EXTRAFLAGS += -I$(BUILDROOT)/libraries/GCS_MAVLink/include/mavlink
+
 # we have different config files for V1 and V2
 PX4_V1_CONFIG_FILE=$(MK_DIR)/PX4/config_px4fmu-v1_APM.mk
 PX4_V2_CONFIG_FILE=$(MK_DIR)/PX4/config_px4fmu-v2_APM.mk