diff --git a/drivers/sensors/Make.defs b/drivers/sensors/Make.defs
index 65d7448d5f..3dcd48fe9d 100644
--- a/drivers/sensors/Make.defs
+++ b/drivers/sensors/Make.defs
@@ -25,11 +25,11 @@ ifeq ($(CONFIG_SENSORS),y)
 CSRCS += sensor.c
 
 ifeq ($(CONFIG_USENSOR),y)
-CSRCS += usensor.c
+  CSRCS += usensor.c
 endif
 
 ifeq ($(CONFIG_SENSORS_RPMSG),y)
-CSRCS += sensor_rpmsg.c
+  CSRCS += sensor_rpmsg.c
 endif
 
 ifeq ($(CONFIG_SENSORS_GPS),y)