diff --git a/Lib/xml/sax/saxutils.py b/Lib/xml/sax/saxutils.py
index 892f34d..9fe8a4a 100644
--- a/Lib/xml/sax/saxutils.py
+++ b/Lib/xml/sax/saxutils.py
@@ -203,8 +203,10 @@
         source = xmlreader.InputSource(source)
     elif hasattr(source, "read"):
         f = source
-        source = xmlreader.InputSource(source)
+        source = xmlreader.InputSource()
         source.setByteStream(f)
+        if hasattr(f, "name"):
+            f.setSystemId(f.name)
 
     if source.getByteStream() is None:
         sysid = source.getSystemId()