diff --git a/src/zabapgit_object_doct.prog.abap b/src/zabapgit_object_doct.prog.abap
index 6700ab155..0e7b928f7 100644
--- a/src/zabapgit_object_doct.prog.abap
+++ b/src/zabapgit_object_doct.prog.abap
@@ -65,6 +65,9 @@ CLASS lcl_object_doct IMPLEMENTATION.
 
   METHOD lif_object~changed_by.
     rv_user = read( )-head-tdluser.
+    IF rv_user IS INITIAL.
+      rv_user = c_user_unknown.
+    ENDIF.    
   ENDMETHOD.                    "lif_object~changed_by
 
   METHOD lif_object~exists.