diff --git a/src/zcl_excel_style_changer.clas.abap b/src/zcl_excel_style_changer.clas.abap
index fca10e2..26a216d 100644
--- a/src/zcl_excel_style_changer.clas.abap
+++ b/src/zcl_excel_style_changer.clas.abap
@@ -5,15 +5,16 @@ CLASS zcl_excel_style_changer DEFINITION
 
   PUBLIC SECTION.
 
-    INTERFACES zif_excel_style_changer .
+    INTERFACES zif_excel_style_changer.
 
     CLASS-METHODS create
       IMPORTING
-        !excel        TYPE REF TO zcl_excel
+        excel         TYPE REF TO zcl_excel
       RETURNING
         VALUE(result) TYPE REF TO zif_excel_style_changer
       RAISING
-        zcx_excel .
+        zcx_excel.
+
   PROTECTED SECTION.
   PRIVATE SECTION.