1 files changed, 1 insertions, 1 deletions
diff --git a/Makefile b/Makefile
index 3bb92798d9..ece0f3d904 100644
--- a/Makefile
+++ b/Makefile
@@ -48,7 +48,7 @@ endif
 _tsk_cfg:=$(foreach t,$(_tsk_lst) ,HAS_TASK_$(t))
 CPPFLAGS+=$(foreach t,$(_tsk_cfg),-D$(t))
 _flag_cfg:=$(shell $(CPP) $(CPPFLAGS) -P -dM -Ichip/$(CHIP) -Iboard/$(BOARD) \
-	include/config.h | grep -o "\#define CONFIG_[A-Za-z0-9_]*" | \
+	include/config.h | grep -o "\#define CONFIG_[A-Z0-9_]*" | \
 	cut -c9- | sort)
 
 $(foreach c,$(_tsk_cfg) $(_flag_cfg),$(eval $(c)=y))