diff --git a/demos/STM32/RT-STM32L476-DISCOVERY-SB_CLIENT/.project b/demos/STM32/RT-STM32L476-DISCOVERY-SB_CLIENT/.project
index 6edbd8183..a84ee8b46 100644
--- a/demos/STM32/RT-STM32L476-DISCOVERY-SB_CLIENT/.project
+++ b/demos/STM32/RT-STM32L476-DISCOVERY-SB_CLIENT/.project
@@ -25,19 +25,9 @@
 	</natures>
 	<linkedResources>
 		<link>
-			<name>board</name>
+			<name>sb</name>
 			<type>2</type>
-			<locationURI>CHIBIOS/os/hal/boards/ST_STM32L476_DISCOVERY</locationURI>
-		</link>
-		<link>
-			<name>os</name>
-			<type>2</type>
-			<locationURI>CHIBIOS/os</locationURI>
-		</link>
-		<link>
-			<name>test</name>
-			<type>2</type>
-			<locationURI>CHIBIOS/test</locationURI>
+			<locationURI>CHIBIOS/os/sb</locationURI>
 		</link>
 	</linkedResources>
 </projectDescription>
diff --git a/demos/STM32/RT-STM32L476-DISCOVERY-SB_CLIENT/main.c b/demos/STM32/RT-STM32L476-DISCOVERY-SB_CLIENT/main.c
index 6b6aa87fb..08c24333f 100644
--- a/demos/STM32/RT-STM32L476-DISCOVERY-SB_CLIENT/main.c
+++ b/demos/STM32/RT-STM32L476-DISCOVERY-SB_CLIENT/main.c
@@ -16,6 +16,7 @@
 
 #include <stdint.h>
 #include <stdbool.h>
+#include <stddef.h>
 
 #include "sbuser.h"
 
@@ -39,6 +40,9 @@ int main(void) {
   }
 #endif
   while (true) {
-    sbSleepMilliseconds(500);
+    msg_t msg = sbMsgWait();
+    sbFileWrite(1U, (const uint8_t *)"Hello World!!\r\n", 15U);
+    sbMsgReply(msg);
+//    sbSleepMilliseconds(500);
   }
 }
diff --git a/demos/STM32/RT-STM32L476-DISCOVERY-SB_HOST/main.c b/demos/STM32/RT-STM32L476-DISCOVERY-SB_HOST/main.c
index 23e8bc624..92083aed7 100644
--- a/demos/STM32/RT-STM32L476-DISCOVERY-SB_HOST/main.c
+++ b/demos/STM32/RT-STM32L476-DISCOVERY-SB_HOST/main.c
@@ -22,6 +22,9 @@
 #include "chprintf.h"
 #include "sbhost.h"
 
+/* SandBox object.*/
+sb_class_t sbx1;
+
 /*
  * LEDs blinker thread, times are in milliseconds.
  */
@@ -39,6 +42,7 @@ static THD_FUNCTION(Thread1, arg) {
     chThdSleepMilliseconds(50);
     palSetLine(LINE_LED_RED);
     chThdSleepMilliseconds(200);
+    (void) sbSendMessage(&sbx1, 0xF00F55AAU);
   }
 }
 
@@ -58,7 +62,6 @@ static THD_FUNCTION(Unprivileged1, arg) {
     .stdout_stream  = (SandboxStream *)&SD2,
     .stderr_stream  = (SandboxStream *)&SD2
   };
-  sb_class_t sbx1;
 
   (void)arg;
   chRegSetThreadName("unprivileged");
@@ -108,7 +111,7 @@ int main(void) {
   sdStart(&SD2, NULL);
 
   /* Creating the blinker thread.*/
-  chThdCreateStatic(waThread1, sizeof(waThread1), NORMALPRIO,
+  chThdCreateStatic(waThread1, sizeof(waThread1), NORMALPRIO+10,
                     Thread1, NULL);
 
   /* Creating the unprivileged thread.*/
diff --git a/os/sb/host/sbapi.h b/os/sb/host/sbapi.h
index 049aaba07..e2a08d789 100644
--- a/os/sb/host/sbapi.h
+++ b/os/sb/host/sbapi.h
@@ -56,6 +56,10 @@ typedef void (*port_syscall_t)(struct port_extctx *ectx);
  *          this subsystem.
  */
 struct SandboxStreamVMT {
+  /**
+   * @brief   Object instance offset.
+   */
+  size_t instance_offset;
   /**
    * @brief   Stream write buffer method.
    */
diff --git a/os/sb/host/sbhost.c b/os/sb/host/sbhost.c
index b31d2c851..1329ef138 100644
--- a/os/sb/host/sbhost.c
+++ b/os/sb/host/sbhost.c
@@ -117,8 +117,9 @@ void sbStart(sb_class_t *sbcp, const sb_config_t *config) {
 
   /* Additional context information.*/
   sbcp->config = config;
-  chThdGetSelfX()->ctx.syscall.p    = (const void *)sbcp;
-  chThdGetSelfX()->ctx.syscall.psp  = __get_PSP();
+  sbcp->tp     = chThdGetSelfX();
+  sbcp->tp->ctx.syscall.p    = (const void *)sbcp;
+  sbcp->tp->ctx.syscall.psp  = __get_PSP();
 
   /* Jumping to the unprivileged code.*/
   port_unprivileged_jump(pc, psp);