diff --git a/boards/diatone/mamba-f405-mk2/nuttx-config/nsh/defconfig b/boards/diatone/mamba-f405-mk2/nuttx-config/nsh/defconfig
index ae2e37b080..7290e1d6b0 100644
--- a/boards/diatone/mamba-f405-mk2/nuttx-config/nsh/defconfig
+++ b/boards/diatone/mamba-f405-mk2/nuttx-config/nsh/defconfig
@@ -175,8 +175,8 @@ CONFIG_SYSTEM_CDCACM=y
 CONFIG_SYSTEM_NSH=y
 CONFIG_TASK_NAME_SIZE=24
 CONFIG_UART4_BAUD=57600
-CONFIG_UART4_RXBUFSIZE=300
-CONFIG_UART4_TXBUFSIZE=900
+CONFIG_UART4_RXBUFSIZE=600
+CONFIG_UART4_TXBUFSIZE=600
 CONFIG_USART1_RXBUFSIZE=300
 CONFIG_USART1_RXDMA=y
 CONFIG_USART1_TXBUFSIZE=300