diff --git a/Lib/tarfile.py b/Lib/tarfile.py
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python3
+usr/bin/env python3
 #-------------------------------------------------------------------
 # tarfile.py
 #-------------------------------------------------------------------
@@ -2153,10 +2153,10 @@
                 for offset, size in tarinfo.sparse:
                     target.seek(offset)
                     copyfileobj(source, target, size, ReadError)
+                target.seek(tarinfo.size)
+                target.truncate()
             else:
                 copyfileobj(source, target, tarinfo.size, ReadError)
-            target.seek(tarinfo.size)
-            target.truncate()
 
     def makeunknown(self, tarinfo, targetpath):
         """Make a file from a TarInfo object with an unknown type