diff --git a/Source/include/mpu_wrappers.h b/Source/include/mpu_wrappers.h
index 49bf7a1..7b44c26 100644
--- a/Source/include/mpu_wrappers.h
+++ b/Source/include/mpu_wrappers.h
@@ -94,14 +94,17 @@
 		#define xQueueGenericReceive			MPU_xQueueGenericReceive
 		#define uxQueueMessagesWaiting			MPU_uxQueueMessagesWaiting
 		#define vQueueDelete					MPU_vQueueDelete
-		#define vQueueAddToRegistry				MPU_vQueueAddToRegistry
-		#define vQueueUnregisterQueue			MPU_vQueueUnregisterQueue
 
 		#define pvPortMalloc					MPU_pvPortMalloc
 		#define vPortFree						MPU_vPortFree
 		#define xPortGetFreeHeapSize			MPU_xPortGetFreeHeapSize
 		#define vPortInitialiseBlocks			MPU_vPortInitialiseBlocks
 
+		#if configQUEUE_REGISTRY_SIZE > 0
+			#define vQueueAddToRegistry				MPU_vQueueAddToRegistry
+			#define vQueueUnregisterQueue			MPU_vQueueUnregisterQueue
+		#endif
+
 		/* Remove the privileged function macro. */
 		#define PRIVILEGED_FUNCTION
 
diff --git a/Source/portable/GCC/ARM_CM3_MPU/port.c b/Source/portable/GCC/ARM_CM3_MPU/port.c
index 93caade..d4a662e 100644
--- a/Source/portable/GCC/ARM_CM3_MPU/port.c
+++ b/Source/portable/GCC/ARM_CM3_MPU/port.c
@@ -91,7 +91,6 @@
 #define portNVIC_PENDSV_PRI						( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16UL )
 #define portNVIC_SYSTICK_PRI					( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )
 #define portNVIC_SVC_PRI						( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )
-#define portNVIC_TEMP_SVC_PRI					( 0x01UL << 24UL )
 
 /* Constants required to set up the initial stack. */
 #define portINITIAL_XPSR						( 0x01000000 )
@@ -270,10 +269,9 @@
  */
 portBASE_TYPE xPortStartScheduler( void )
 {
-	/* Make PendSV, CallSV and SysTick the same priroity as the kernel. */
+	/* Make PendSV and SysTick the same priroity as the kernel. */
 	*(portNVIC_SYSPRI2) |= portNVIC_PENDSV_PRI;
 	*(portNVIC_SYSPRI2) |= portNVIC_SYSTICK_PRI;
-    *(portNVIC_SYSPRI1) |= portNVIC_TEMP_SVC_PRI;
 
 	/* Configure the regions in the MPU that are common to all tasks. */
 	prvSetupMPU();