diff --git a/pkg/archive.py b/pkg/archive.py
index 61727204..9c15f065 100644
--- a/pkg/archive.py
+++ b/pkg/archive.py
@@ -146,7 +146,7 @@ def __init__(self,
       # Instead, we manually re-implement gzopen from tarfile.py and set mtime.
       self.fileobj = gzip.GzipFile(
           filename=name, mode='w', compresslevel=9, mtime=self.default_mtime)
-    self.tar = tarfile.open(name=name, mode=mode, fileobj=self.fileobj)
+    self.tar = tarfile.open(name=name, mode=mode, fileobj=self.fileobj, format=tarfile.GNU_FORMAT)
     self.members = set([])
     self.directories = set([])
 
diff --git a/pkg/make_deb.py b/pkg/make_deb.py
index d34ac755..61340b59 100644
--- a/pkg/make_deb.py
+++ b/pkg/make_deb.py
@@ -146,7 +146,7 @@ def CreateDebControl(extrafiles=None, **kwargs):
   # Create the control.tar file
   tar = BytesIO()
   with gzip.GzipFile('control.tar.gz', mode='w', fileobj=tar, mtime=0) as gz:
-    with tarfile.open('control.tar.gz', mode='w', fileobj=gz) as f:
+    with tarfile.open('control.tar.gz', mode='w', fileobj=gz, format=tarfile.GNU_FORMAT) as f:
       tarinfo = tarfile.TarInfo('./control')
       control_file_data = controlfile.encode('utf-8')
       tarinfo.size = len(control_file_data)