diff --git a/configs/v38b_defconfig b/configs/v38b_defconfig
index 9440b8c..9470628 100644
--- a/configs/v38b_defconfig
+++ b/configs/v38b_defconfig
@@ -10,6 +10,7 @@
 CONFIG_CMD_MII=y
 CONFIG_CMD_PING=y
 CONFIG_CMD_FAT=y
+CONFIG_CMD_DIAG=y
 CONFIG_MAC_PARTITION=y
 CONFIG_LED_STATUS=y
 CONFIG_LED_STATUS0=y