diff --git a/libraries/AP_Common/Arduino.mk b/libraries/AP_Common/Arduino.mk
index 3485b2b763..497b68b22d 100644
--- a/libraries/AP_Common/Arduino.mk
+++ b/libraries/AP_Common/Arduino.mk
@@ -27,16 +27,6 @@
 # Build an Arduino sketch.
 #
 
-################################################################################
-# Config options
-#
-# The Makefile calling us must specify BOARD
-#
-HARDWARE		?=	arduino
-ifeq ($(BOARD),)
-$(error ERROR: must set BOARD before including this file)
-endif
-
 ################################################################################
 # Paths
 #
@@ -82,6 +72,18 @@ SKETCH			:=	$(lastword $(subst /, ,$(SRCROOT)))
 TMPDIR			?=	/tmp
 BUILDROOT		:=	$(abspath $(TMPDIR)/$(SKETCH).build)
 
+
+################################################################################
+# Config options
+#
+# The Makefile calling us must specify BOARD
+#
+include $(TMPDIR)/config.mk
+HARDWARE		?=	arduino
+ifeq ($(BOARD),)
+$(error ERROR: must set BOARD before including this file)
+endif
+
 #
 # Find Arduino, if not explicitly specified
 #