diff --git a/configs/xenguest_arm64_defconfig b/configs/xenguest_arm64_defconfig
index 4997c25..11fca09 100644
--- a/configs/xenguest_arm64_defconfig
+++ b/configs/xenguest_arm64_defconfig
@@ -3,6 +3,7 @@
 CONFIG_TARGET_XENGUEST_ARM64=y
 CONFIG_SYS_TEXT_BASE=0x40080000
 CONFIG_SYS_MALLOC_LEN=0x2000000
+CONFIG_SYS_MALLOC_F_LEN=0x400
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_DEFAULT_DEVICE_TREE="xenguest-arm64"
 CONFIG_IDENT_STRING=" xenguest"