diff --git a/src/zcl_excel_common.clas.abap b/src/zcl_excel_common.clas.abap
index 75e8b9e..1fd4ccf 100644
--- a/src/zcl_excel_common.clas.abap
+++ b/src/zcl_excel_common.clas.abap
@@ -1075,6 +1075,9 @@ CLASS zcl_excel_common IMPLEMENTATION.
     DESCRIBE FIELD i_source TYPE type_kind.
     flag_class = boolc( type_kind = cl_abap_typedescr=>typekind_oref ).
 
+*   Only borders will be passed as unbound references.
+    CHECK flag_class = abap_false OR i_source IS NOT INITIAL.  " Exit if unbound reference
+
     descr ?= cl_abap_structdescr=>describe_by_data( e_target ).
 
     LOOP AT descr->components INTO wa_component.
@@ -1086,10 +1089,6 @@ CLASS zcl_excel_common IMPLEMENTATION.
       IF flag_class = abap_false.
 * source is a structure - use assign component
         ASSIGN COMPONENT wa_component-name OF STRUCTURE i_source TO <attribute>.
-      ELSEIF i_source IS INITIAL.
-        CLEAR <field>.
-        CLEAR <fieldx> WITH abap_true.
-        CONTINUE.
       ELSE.
 * then it is an attribute of the class - use different assign then
         CONCATENATE 'i_source->' wa_component-name INTO attribute_name.
@@ -1130,6 +1129,7 @@ CLASS zcl_excel_common IMPLEMENTATION.
 
     DESCRIBE FIELD e_target TYPE type_kind.
     flag_class = boolc( type_kind = cl_abap_typedescr=>typekind_oref ).
+
     IF flag_class = abap_true AND e_target IS INITIAL.
 * Only borders will be passed as unbound references. But since we want to set a value we have to create an instance
       CREATE OBJECT o_border.