diff --git a/src/zcl_excel_reader_xlsm.clas.abap b/src/zcl_excel_reader_xlsm.clas.abap
index 816e5ee..d3f9e1f 100644
--- a/src/zcl_excel_reader_xlsm.clas.abap
+++ b/src/zcl_excel_reader_xlsm.clas.abap
@@ -22,7 +22,9 @@ private section.
   methods LOAD_VBAPROJECT
     importing
       !IP_PATH type STRING
-      !IP_EXCEL type ref to ZCL_EXCEL .
+      !IP_EXCEL type ref to ZCL_EXCEL
+    raising
+      ZCX_EXCEL .
 ENDCLASS.