diff --git a/configs/open1788/kernel/up_userspace.c b/configs/open1788/kernel/up_userspace.c
index 62c83e735a7..e2cb8c0132c 100644
--- a/configs/open1788/kernel/up_userspace.c
+++ b/configs/open1788/kernel/up_userspace.c
@@ -44,6 +44,7 @@
 #include <nuttx/userspace.h>
 #include <nuttx/wqueue.h>
 #include <nuttx/mm.h>
+#include <nuttx/sched.h>
 
 #if defined(CONFIG_NUTTX_KERNEL) && !defined(__KERNEL__)
 
@@ -101,6 +102,10 @@ const struct userspace_s userspace __attribute__ ((section (".userspace"))) =
   .us_bssstart      = (uintptr_t)&_sbss,
   .us_bssend        = (uintptr_t)&_ebss,
 
+  /* Task/thread startup stubs */
+
+  .task_startup     = task_startup,
+
   /* Memory manager entry points (declared in include/nuttx/mm.h) */
 
   .mm_initialize    = umm_initialize,
diff --git a/configs/open1788/knsh/defconfig b/configs/open1788/knsh/defconfig
index 22042073c32..50b4e3d6d7e 100755
--- a/configs/open1788/knsh/defconfig
+++ b/configs/open1788/knsh/defconfig
@@ -344,7 +344,7 @@ CONFIG_IDLETHREAD_STACKSIZE=1024
 CONFIG_USERMAIN_STACKSIZE=2048
 CONFIG_PTHREAD_STACK_MIN=256
 CONFIG_PTHREAD_STACK_DEFAULT=2048
-CONFIG_SYS_RESERVED=4
+CONFIG_SYS_RESERVED=5
 
 #
 # Device Drivers
diff --git a/configs/sam3u-ek/knsh/defconfig b/configs/sam3u-ek/knsh/defconfig
index 93d436e5478..7146ef6bf3d 100755
--- a/configs/sam3u-ek/knsh/defconfig
+++ b/configs/sam3u-ek/knsh/defconfig
@@ -249,7 +249,7 @@ CONFIG_IDLETHREAD_STACKSIZE=1024
 CONFIG_USERMAIN_STACKSIZE=2048
 CONFIG_PTHREAD_STACK_MIN=256
 CONFIG_PTHREAD_STACK_DEFAULT=2048
-CONFIG_SYS_RESERVED=4
+CONFIG_SYS_RESERVED=5
 
 #
 # Device Drivers