diff --git a/portable/GCC/MicroBlaze/portmacro.h b/portable/GCC/MicroBlaze/portmacro.h
index 7d96d5c..c646496 100644
--- a/portable/GCC/MicroBlaze/portmacro.h
+++ b/portable/GCC/MicroBlaze/portmacro.h
@@ -115,6 +115,7 @@
 #define portSTACK_GROWTH            ( -1 )
 #define portTICK_PERIOD_MS          ( ( TickType_t ) 1000 / configTICK_RATE_HZ )
 #define portNOP()                   asm volatile ( "NOP" )
+#define portMEMORY_BARRIER()        asm volatile ( "" ::: "memory" )
 /*-----------------------------------------------------------*/
 
 /* Task function macros as described on the FreeRTOS.org WEB site. */
diff --git a/portable/GCC/MicroBlazeV8/portmacro.h b/portable/GCC/MicroBlazeV8/portmacro.h
index a423733..be9dfac 100644
--- a/portable/GCC/MicroBlazeV8/portmacro.h
+++ b/portable/GCC/MicroBlazeV8/portmacro.h
@@ -152,6 +152,7 @@
 #define portSTACK_GROWTH            ( -1 )
 #define portTICK_PERIOD_MS          ( ( TickType_t ) 1000 / configTICK_RATE_HZ )
 #define portNOP()                   asm volatile ( "NOP" )
+#define portMEMORY_BARRIER()        asm volatile ( "" ::: "memory" )
 /*-----------------------------------------------------------*/
 
 /* Task function macros as described on the FreeRTOS.org WEB site. */
diff --git a/portable/GCC/MicroBlazeV9/portmacro.h b/portable/GCC/MicroBlazeV9/portmacro.h
index 84b358f..c26daa7 100644
--- a/portable/GCC/MicroBlazeV9/portmacro.h
+++ b/portable/GCC/MicroBlazeV9/portmacro.h
@@ -152,6 +152,7 @@
 #define portSTACK_GROWTH            ( -1 )
 #define portTICK_PERIOD_MS          ( ( TickType_t ) 1000 / configTICK_RATE_HZ )
 #define portNOP()                   asm volatile ( "NOP" )
+#define portMEMORY_BARRIER()        asm volatile ( "" ::: "memory" )
 /*-----------------------------------------------------------*/
 
 #if( XPAR_MICROBLAZE_USE_STACK_PROTECTION )