diff --git a/boards/mro/x21-777/nuttx-config/nsh/defconfig b/boards/mro/x21-777/nuttx-config/nsh/defconfig
index 3b297d4bfc..8f5a1e438b 100644
--- a/boards/mro/x21-777/nuttx-config/nsh/defconfig
+++ b/boards/mro/x21-777/nuttx-config/nsh/defconfig
@@ -86,6 +86,7 @@ CONFIG_LIBC_STRERROR=y
 CONFIG_FS_PROCFS_MAX_TASKS=64
 CONFIG_MEMSET_64BIT=y
 CONFIG_MEMSET_OPTSPEED=y
+CONFIG_MKFATFS_BUFFER_ALIGMENT=32
 CONFIG_MMCSD=y
 CONFIG_MMCSD_SDIO=y
 CONFIG_MMCSD_SDIOWAIT_WRCOMPLETE=y