diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index 540ccef..4e33222 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -352,6 +352,7 @@
 CONFIG_FS_CRAMFS=y
 CONFIG_ADDR_MAP=y
 CONFIG_CMD_DHRYSTONE=y
+CONFIG_MBEDTLS_LIB=y
 CONFIG_ECDSA=y
 CONFIG_ECDSA_VERIFY=y
 CONFIG_TPM=y