diff --git a/nuttx-configs/zubaxgnss-v1/bootloader/defconfig b/nuttx-configs/zubaxgnss-v1/bootloader/defconfig
index da883c075b..1fb601bfca 100644
--- a/nuttx-configs/zubaxgnss-v1/bootloader/defconfig
+++ b/nuttx-configs/zubaxgnss-v1/bootloader/defconfig
@@ -597,6 +597,7 @@ CONFIG_FDCLONE_STDIO=y
 CONFIG_SDCLONE_DISABLE=y
 CONFIG_NFILE_DESCRIPTORS=0
 CONFIG_NFILE_STREAMS=0
+CONFIG_STDIO_DISABLE_BUFFERING=y
 CONFIG_NAME_MAX=0
 # CONFIG_PRIORITY_INHERITANCE is not set
 
@@ -772,7 +773,7 @@ CONFIG_SYMTAB_ORDEREDBYNAME=y
 #
 # Standard C Library Options
 #
-CONFIG_STDIO_BUFFER_SIZE=64
+# CONFIG_STDIO_BUFFER_SIZE is not set
 # CONFIG_STDIO_LINEBUFFER is not set
 CONFIG_NUNGET_CHARS=0
 # CONFIG_LIBC_DLLFCN is not set