diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index 7b5ef2b..2598017 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -37,5 +37,6 @@
 CONFIG_USB_STORAGE=y
 CONFIG_DM_RTC=y
 CONFIG_ERRNO_STR=y
+CONFIG_UNIT_TEST=y
 CONFIG_UT_TIME=y
 CONFIG_UT_DM=y