diff --git a/ClosedXML/Excel/XLWorkbook.cs b/ClosedXML/Excel/XLWorkbook.cs
index 3473220..abec6c3 100644
--- a/ClosedXML/Excel/XLWorkbook.cs
+++ b/ClosedXML/Excel/XLWorkbook.cs
@@ -992,5 +992,10 @@
         {
             Protect(false, false, workbookPassword);
         }
+
+        public override string ToString()
+        {
+            return _originalFile ?? String.Format("XLWorkbook({0})", _originalStream.ToString());
+        }
     }
 }