diff --git a/setup.cfg b/setup.cfg
index b011a7e..d6269ab 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -58,7 +58,7 @@ classifiers =
     Programming Language :: Python
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3 :: Only
-    Topic :: System :: Shell
+    Topic :: System :: Shells
 
 
 [options]
diff --git a/tools/build_release b/tools/build_release
index 51fd87d..970a5a0 100755
--- a/tools/build_release
+++ b/tools/build_release
@@ -17,6 +17,7 @@ def build_release():
     sh(sdists)
     buildwheels()
     sh(' '.join([sys.executable, 'tools/retar.py', 'dist/*.gz']))
+    sh(' '.join([sys.executable, 'tools/retar.py', 'dist/*.xz']))
 
 if __name__ == '__main__':
     build_release()
diff --git a/tools/release b/tools/release
index 2de8e12..2ba4d24 100755
--- a/tools/release
+++ b/tools/release
@@ -63,7 +63,7 @@ if 'upload' in sys.argv:
     # Make target dir if it doesn't exist
     print('1. Uploading IPython to archive.ipython.org')
     sh('ssh %s "mkdir -p %s/release/%s" ' % (archive_user, archive_dir, version))
-    sh('scp *.tar.gz *.whl %s' % release_site)
+    sh('scp *.tar.gz *.tar.xz *.whl %s' % release_site)
 
     print('2. Uploading backup files...')
     cd(ipbackupdir)
diff --git a/tools/retar.py b/tools/retar.py
index b81345d..dbc4f0b 100644
--- a/tools/retar.py
+++ b/tools/retar.py
@@ -35,7 +35,11 @@ old_buf = io.BytesIO()
 with open(path, "rb") as f:
     old_buf.write(f.read())
 old_buf.seek(0)
-old = tarfile.open(fileobj=old_buf, mode="r:gz")
+if path.name.endswith("gz"):
+    r_mode = "r:gz"
+if path.name.endswith(("xz", "xz2")):
+    r_mode = "r:xz"
+old = tarfile.open(fileobj=old_buf, mode=r_mode)
 
 buf = io.BytesIO()
 new = tarfile.open(fileobj=buf, mode="w", format=tarfile.GNU_FORMAT)
@@ -46,6 +50,7 @@ for i, m in enumerate(old):
         continue
     m2 = tarfile.TarInfo(m.name)
     m2.mtime = min(timestamp, m.mtime)
+    m2.pax_headers["mtime"] = m2.mtime
     m2.size = m.size
     m2.type = m.type
     m2.linkname = m.linkname
@@ -59,9 +64,19 @@ new.close()
 old.close()
 
 buf.seek(0)
-with open(path, "wb") as f:
-    with gzip.GzipFile('', "wb", fileobj=f, mtime=timestamp) as gzf:
-        gzf.write(buf.read())
+
+if r_mode == "r:gz":
+    with open(path, "wb") as f:
+        with gzip.GzipFile("", "wb", fileobj=f, mtime=timestamp) as gzf:
+            gzf.write(buf.read())
+elif r_mode == "r:xz":
+    import lzma
+
+    with lzma.open(path, "wb") as f:
+        f.write(buf.read())
+
+else:
+    assert False
 
 # checks the archive is valid.
 archive = tarfile.open(path)
diff --git a/tools/toollib.py b/tools/toollib.py
index 1555e55..ce37644 100644
--- a/tools/toollib.py
+++ b/tools/toollib.py
@@ -18,7 +18,7 @@ archive = '%s:%s' % (archive_user, archive_dir)
 
 # Build commands
 # Source dists
-sdists = "{python} setup.py sdist --formats=xztar".format(python=sys.executable)
+sdists = "{python} setup.py sdist --formats=xztar,gztar".format(python=sys.executable)
 # Binary dists
 def buildwheels():
     sh("{python} setup.py bdist_wheel".format(python=sys.executable))