diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 59e8d0d..6072fa1 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -3,7 +3,7 @@
 # Copyright (c) 2016, NVIDIA CORPORATION.
 #
 
-obj-$(CONFIG_$(SPL_)DM_MAILBOX) += mailbox-uclass.o
+obj-$(CONFIG_$(XPL_)DM_MAILBOX) += mailbox-uclass.o
 obj-$(CONFIG_APPLE_MBOX) += apple-mbox.o
 obj-$(CONFIG_SANDBOX_MBOX) += sandbox-mbox.o
 obj-$(CONFIG_SANDBOX_MBOX) += sandbox-mbox-test.o