diff --git a/configs/sipeed_maix_smode_defconfig b/configs/sipeed_maix_smode_defconfig
index cd4d105..36c2dbb 100644
--- a/configs/sipeed_maix_smode_defconfig
+++ b/configs/sipeed_maix_smode_defconfig
@@ -12,6 +12,7 @@
 CONFIG_USE_BOOTCOMMAND=y
 CONFIG_BOOTCOMMAND="run k210_bootcmd"
 CONFIG_HUSH_PARSER=y
+CONFIG_SYS_CBSIZE=256
 CONFIG_SYS_PBSIZE=276
 CONFIG_MTDIDS_DEFAULT="nor0=spi3:0"
 CONFIG_MTDPARTS_DEFAULT="nor0:1M(u-boot),0x1000@0xfff000(env)"