diff --git a/nuttx-configs/px4fmu-v1/nsh/defconfig b/nuttx-configs/px4fmu-v1/nsh/defconfig
index 874615d3b2..9692a854bc 100644
--- a/nuttx-configs/px4fmu-v1/nsh/defconfig
+++ b/nuttx-configs/px4fmu-v1/nsh/defconfig
@@ -420,7 +420,7 @@ CONFIG_PREALLOC_TIMERS=50
 # Stack and heap information
 #
 CONFIG_IDLETHREAD_STACKSIZE=1000
-CONFIG_USERMAIN_STACKSIZE=3000
+CONFIG_USERMAIN_STACKSIZE=2500
 CONFIG_PTHREAD_STACK_MIN=512
 CONFIG_PTHREAD_STACK_DEFAULT=2048
 
@@ -518,8 +518,8 @@ CONFIG_USART1_2STOP=0
 #
 # USART2 Configuration
 #
-CONFIG_USART2_RXBUFSIZE=512
-CONFIG_USART2_TXBUFSIZE=512
+CONFIG_USART2_RXBUFSIZE=300
+CONFIG_USART2_TXBUFSIZE=300
 CONFIG_USART2_BAUD=57600
 CONFIG_USART2_BITS=8
 CONFIG_USART2_PARITY=0
@@ -586,8 +586,8 @@ CONFIG_CDCACM_EPBULKIN_HSSIZE=512
 CONFIG_CDCACM_NWRREQS=4
 CONFIG_CDCACM_NRDREQS=4
 CONFIG_CDCACM_BULKIN_REQLEN=96
-CONFIG_CDCACM_RXBUFSIZE=512
-CONFIG_CDCACM_TXBUFSIZE=2048
+CONFIG_CDCACM_RXBUFSIZE=300
+CONFIG_CDCACM_TXBUFSIZE=1800
 CONFIG_CDCACM_VENDORID=0x26ac
 CONFIG_CDCACM_PRODUCTID=0x0010
 CONFIG_CDCACM_VENDORSTR="3D Robotics"
diff --git a/nuttx-configs/px4fmu-v2/nsh/defconfig b/nuttx-configs/px4fmu-v2/nsh/defconfig
index 8f6af5d6b4..db7c41dae0 100644
--- a/nuttx-configs/px4fmu-v2/nsh/defconfig
+++ b/nuttx-configs/px4fmu-v2/nsh/defconfig
@@ -455,7 +455,7 @@ CONFIG_PREALLOC_TIMERS=50
 # Stack and heap information
 #
 CONFIG_IDLETHREAD_STACKSIZE=1000
-CONFIG_USERMAIN_STACKSIZE=3000
+CONFIG_USERMAIN_STACKSIZE=2500
 CONFIG_PTHREAD_STACK_MIN=512
 CONFIG_PTHREAD_STACK_DEFAULT=2048