diff --git a/third-party/py/pex/pex/common.py b/third-party/py/pex/pex/common.py
index 76459ce23..eff411b20 100644
--- a/third-party/py/pex/pex/common.py
+++ b/third-party/py/pex/pex/common.py
@@ -328,4 +328,7 @@ class Chroot(object):
   def zip(self, filename, mode='wb'):
     with contextlib.closing(zipfile.ZipFile(filename, mode)) as zf:
       for f in sorted(self.files()):
-        zf.write(os.path.join(self.chroot, f), arcname=f, compress_type=zipfile.ZIP_DEFLATED)
+        path = os.path.join(self.chroot, f)
+        instant = 615532801
+        os.utime(path, (instant, instant))
+        zf.write(path, arcname=f, compress_type=zipfile.ZIP_DEFLATED)