diff --git a/csl/stm32f042k6t6/implementation/imp_timer.c b/csl/stm32f042k6t6/implementation/imp_timer.c
index caf60f9..926188b 100644
--- a/csl/stm32f042k6t6/implementation/imp_timer.c
+++ b/csl/stm32f042k6t6/implementation/imp_timer.c
@@ -11,7 +11,7 @@
 			// clear flag
             (flagReg) &= ~(flagMask);\
 			// indext to corresponding handler and execute
-            ((intHandler_t)(intHandlerList[intType]))();\
+            ((intHandler_t)(intHandlerList[(intType)]))();\
         }\
     } while (0)