diff --git a/configs/arduino-mega2560/nsh/defconfig b/configs/arduino-mega2560/nsh/defconfig
index a691d327f2f..d5d59b96465 100644
--- a/configs/arduino-mega2560/nsh/defconfig
+++ b/configs/arduino-mega2560/nsh/defconfig
@@ -82,9 +82,14 @@ CONFIG_ARCH_FAMILY_AVR=y
 #
 # AVR Configuration Options
 #
-CONFIG_AVR_WINAVR_TOOLCHAIN=y
-# CONFIG_AVR_ATMEL_AVR_TOOLCHAIN is not set
+# CONFIG_AVR_WINAVR_TOOLCHAIN is not set
+CONFIG_AVR_ATMEL_AVR_TOOLCHAIN=y
 # CONFIG_AVR_BUILDROOT_TOOLCHAIN is not set
+
+#
+# Atmel AVR Toolchain options
+#
+# CONFIG_AVR_HAS_MEMX_PTR is not set
 # CONFIG_AVR_USART1 is not set
 
 #
@@ -247,7 +252,7 @@ CONFIG_NAME_MAX=32
 # Stack and heap information
 #
 CONFIG_IDLETHREAD_STACKSIZE=128
-CONFIG_USERMAIN_STACKSIZE=128
+CONFIG_USERMAIN_STACKSIZE=768
 CONFIG_PTHREAD_STACK_MIN=128
 CONFIG_PTHREAD_STACK_DEFAULT=128
 # CONFIG_LIB_SYSCALL is not set
@@ -450,8 +455,8 @@ CONFIG_LIB_RAND_ORDER=1
 # CONFIG_EOL_IS_BOTH_CRLF is not set
 CONFIG_EOL_IS_EITHER_CRLF=y
 # CONFIG_LIBC_EXECFUNCS is not set
-CONFIG_POSIX_SPAWN_PROXY_STACKSIZE=1024
-CONFIG_TASK_SPAWN_DEFAULT_STACKSIZE=2048
+CONFIG_POSIX_SPAWN_PROXY_STACKSIZE=512
+CONFIG_TASK_SPAWN_DEFAULT_STACKSIZE=768
 # CONFIG_LIBC_STRERROR is not set
 # CONFIG_LIBC_PERROR_STDOUT is not set
 CONFIG_ARCH_LOWPUTC=y
@@ -679,7 +684,3 @@ CONFIG_READLINE_ECHO=y
 # CONFIG_SYSTEM_SUDOKU is not set
 # CONFIG_SYSTEM_VI is not set
 # CONFIG_SYSTEM_ZMODEM is not set
-
-# Application configuration
-
-CONFIG_APPS_DIR="../apps"