diff --git a/Lib/tarfile.py b/Lib/tarfile.py
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -1806,7 +1806,7 @@
         return t
 
     @classmethod
-    def xzopen(cls, name, mode="r", fileobj=None, preset=9, **kwargs):
+    def xzopen(cls, name, mode="r", fileobj=None, preset=6, **kwargs):
         """Open lzma compressed tar archive name for reading or writing.
            Appending is not allowed.
         """