diff --git a/configs/sipeed_maix_smode_defconfig b/configs/sipeed_maix_smode_defconfig
index fce628d..2ab0672 100644
--- a/configs/sipeed_maix_smode_defconfig
+++ b/configs/sipeed_maix_smode_defconfig
@@ -3,6 +3,7 @@
 CONFIG_ENV_SIZE=0x1000
 CONFIG_ENV_OFFSET=0xfff000
 CONFIG_ENV_SECT_SIZE=0x1000
+CONFIG_SYS_MALLOC_LEN=0x20000
 CONFIG_TARGET_SIPEED_MAIX=y
 CONFIG_ARCH_RV64I=y
 CONFIG_RISCV_SMODE=y