diff --git a/makefiles/setup.mk b/makefiles/setup.mk
index fdb1612014..168e41a5cb 100644
--- a/makefiles/setup.mk
+++ b/makefiles/setup.mk
@@ -45,6 +45,7 @@ export PX4_INCLUDE_DIR	 = $(abspath $(PX4_BASE)/src/include)/
 export PX4_MODULE_SRC	 = $(abspath $(PX4_BASE)/src)/
 export PX4_MK_DIR	 = $(abspath $(PX4_BASE)/makefiles)/
 export NUTTX_SRC	 = $(abspath $(PX4_BASE)/NuttX/nuttx)/
+export NUTTX_APP_SRC	 = $(abspath $(PX4_BASE)/NuttX/apps)/
 export MAVLINK_SRC	 = $(abspath $(PX4_BASE)/mavlink)/
 export ROMFS_SRC	 = $(abspath $(PX4_BASE)/ROMFS)/
 export IMAGE_DIR	 = $(abspath $(PX4_BASE)/Images)/