diff --git a/lib/sam/3a/Makefile b/lib/sam/3a/Makefile
index 6d3a788d..d3e558c3 100644
--- a/lib/sam/3a/Makefile
+++ b/lib/sam/3a/Makefile
@@ -18,6 +18,7 @@
 ##
 
 LIBNAME		= libopencm3_sam3a
+SRCLIBDIR	?= ../..
 
 PREFIX		?= arm-none-eabi