diff --git a/Makefile.defs b/Makefile.defs
index 5a131c971..397e25561 100644
--- a/Makefile.defs
+++ b/Makefile.defs
@@ -38,8 +38,8 @@ TAR = tar
 TARFLAGS ?= -v --ignore-failed-read -r
 TARFLAGS += -C .. -f
 CROSS  ?= arm-none-eabi-
-CC = gcc
-CXX = g++
+CC ?= gcc
+CXX ?= g++
 LD = g++
 SH = sh
 BASH = bash