diff --git a/examples/FunctionInterruptSimulation/FunctionInterruptSimulation.cpp b/examples/FunctionInterruptSimulation/FunctionInterruptSimulation.cpp
index 186f4542..cee73877 100644
--- a/examples/FunctionInterruptSimulation/FunctionInterruptSimulation.cpp
+++ b/examples/FunctionInterruptSimulation/FunctionInterruptSimulation.cpp
@@ -10,8 +10,9 @@ enum VectorId
   TIM3_IRQ_HANDLER    = 44,
   USART1_IRQ_HANDLER  = 52,
   USART2_IRQ_HANDLER  = 53,
-  VECTOR_ID_RANGE     = USART2_IRQ_HANDLER - TIM1_CC_IRQ_HANDLER + 1,
-  VECTOR_ID_OFFSET    = TIM1_CC_IRQ_HANDLER
+  VECTOR_ID_END,
+  VECTOR_ID_OFFSET    = TIM1_CC_IRQ_HANDLER,
+  VECTOR_ID_RANGE     = VECTOR_ID_END - VECTOR_ID_OFFSET
 };
 
 typedef etl::callback_service<VECTOR_ID_RANGE, VECTOR_ID_OFFSET> InterruptVectors;