diff --git a/ClosedXML/Excel/XLWorkbook.cs b/ClosedXML/Excel/XLWorkbook.cs
index 1177678..3473220 100644
--- a/ClosedXML/Excel/XLWorkbook.cs
+++ b/ClosedXML/Excel/XLWorkbook.cs
@@ -523,6 +523,7 @@
 
             _loadSource = XLLoadSource.File;
             _originalFile = file;
+            _originalStream = null;
         }
 
         private static SpreadsheetDocumentType GetSpreadsheetDocumentType(string filePath)
@@ -624,6 +625,7 @@
 
             _loadSource = XLLoadSource.Stream;
             _originalStream = stream;
+            _originalFile = null;
         }
 
         internal static void CopyStream(Stream input, Stream output)