diff --git a/portable/GCC/ARM_CM3/portmacro.h b/portable/GCC/ARM_CM3/portmacro.h
index 757e44fd9..3d46e0911 100644
--- a/portable/GCC/ARM_CM3/portmacro.h
+++ b/portable/GCC/ARM_CM3/portmacro.h
@@ -171,7 +171,7 @@ extern void vPortExitCritical( void );
 
 /*-----------------------------------------------------------*/
 
-#ifdef configASSERT
+#if configASSERT_DEFINED == 1
     void vPortValidateInterruptPriority( void );
     #define portASSERT_IF_INTERRUPT_PRIORITY_INVALID()    vPortValidateInterruptPriority()
 #endif