diff --git a/configs/sfr_nb4-ser_ram_defconfig b/configs/sfr_nb4-ser_ram_defconfig
index 07f0289..13da31e 100644
--- a/configs/sfr_nb4-ser_ram_defconfig
+++ b/configs/sfr_nb4-ser_ram_defconfig
@@ -21,6 +21,7 @@
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="NB4-SER # "
 CONFIG_SYS_MAXARGS=24
+CONFIG_SYS_CBSIZE=512
 CONFIG_SYS_PBSIZE=539
 CONFIG_CMD_CPU=y
 CONFIG_CMD_LICENSE=y