diff --git a/Makefile b/Makefile
index d92438166f..0ed93e600d 100644
--- a/Makefile
+++ b/Makefile
@@ -426,6 +426,7 @@ unexport O
 unexport GCC_COLORS
 unexport PLATFORM
 unexport OS
+unexport DEVICE_TREE
 
 GNU_HOST_NAME := $(shell support/gnuconfig/config.guess)