diff --git a/Source/portable/IAR/V850ES_Fx3/portmacro.h b/Source/portable/IAR/V850ES_Fx3/portmacro.h
index 4beee153b..55a802b13 100644
--- a/Source/portable/IAR/V850ES_Fx3/portmacro.h
+++ b/Source/portable/IAR/V850ES_Fx3/portmacro.h
@@ -130,6 +130,9 @@ extern void portRESTORE_CONTEXT( void );
 //#define portYIELD()	vPortYield()
 #define portYIELD()	__asm ( "trap 0" )
 #define portNOP()	__asm ( "NOP" )
+extern void vTaskSwitchContext( void );
+#define portYIELD_FROM_ISR( xHigherPriorityTaskWoken ) if( xHigherPriorityTaskWoken ) vTaskSwitchContext();
+
 /*-----------------------------------------------------------*/
 
 /* Hardwware specifics. */