diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 2888bb0acadd..7b604f4926fc 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -1,4 +1,4 @@
-ccflags-$(CONFIG_POWER_SUPPLY_DEBUG) := -DDEBUG
+subdir-ccflags-$(CONFIG_POWER_SUPPLY_DEBUG) := -DDEBUG
 
 power_supply-y				:= power_supply_core.o
 power_supply-$(CONFIG_SYSFS)		+= power_supply_sysfs.o