diff --git a/FreeRTOS/Demo/MicroBlaze_Kintex7_EthernetLite/RTOSDemo/src/serial.c b/FreeRTOS/Demo/MicroBlaze_Kintex7_EthernetLite/RTOSDemo/src/serial.c
index 3d96be5a5f..90ffe0fe96 100644
--- a/FreeRTOS/Demo/MicroBlaze_Kintex7_EthernetLite/RTOSDemo/src/serial.c
+++ b/FreeRTOS/Demo/MicroBlaze_Kintex7_EthernetLite/RTOSDemo/src/serial.c
@@ -210,7 +210,7 @@ portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
 
 static void prvTxHandler( void *pvUnused, unsigned portBASE_TYPE uxUnused )
 {
-BaseType_t xHigherPriorityTaskWoken = NULL;
+BaseType_t xHigherPriorityTaskWoken = ( BaseType_t ) NULL;
 
 	( void ) pvUnused;
 	( void ) uxUnused;
diff --git a/FreeRTOS/Source/portable/GCC/MicroBlazeV9/port.c b/FreeRTOS/Source/portable/GCC/MicroBlazeV9/port.c
index 0460e46d29..f30b9e4574 100644
--- a/FreeRTOS/Source/portable/GCC/MicroBlazeV9/port.c
+++ b/FreeRTOS/Source/portable/GCC/MicroBlazeV9/port.c
@@ -47,7 +47,7 @@ the scheduler being commenced interrupts should not be enabled, so the critical
 nesting variable is initialised to a non-zero value. */
 #define portINITIAL_NESTING_VALUE	( 0xff )
 
-/* The bit within the MSR register that enabled/disables interrupts and 
+/* The bit within the MSR register that enabled/disables interrupts and
 exceptions respectively. */
 #define portMSR_IE					( 0x02U )
 #define portMSR_EE					( 0x100U )
@@ -131,7 +131,7 @@ extern void _start1( void );
 	disabled.  Each task will enable interrupts automatically when it enters
 	the running state for the first time. */
 	*pxTopOfStack = mfmsr() & ~portMSR_IE;
-	
+
 	#if( MICROBLAZE_EXCEPTIONS_ENABLED == 1 )
 	{
 		/* Ensure exceptions are enabled for the task. */
@@ -305,7 +305,13 @@ int32_t lReturn;
 	lReturn = prvEnsureInterruptControllerIsInitialised();
 	if( lReturn == pdPASS )
 	{
-		XIntc_Enable( &xInterruptControllerInstance, ucInterruptID );
+		/* Critical section protects read/modify/writer operation inside
+		XIntc_Enable(). */
+		portENTER_CRITICAL();
+		{
+			XIntc_Enable( &xInterruptControllerInstance, ucInterruptID );
+		}
+		portEXIT_CRITICAL();
 	}
 
 	configASSERT( lReturn );