diff --git a/setup.py b/setup.py
index 140a8b8f25b7513ae4f44af4aca5ac01b93daab6_c2V0dXAucHk=..c4b37a06bf9bdaace58db4b1d4606fb4db59f9be_c2V0dXAucHk= 100644
--- a/setup.py
+++ b/setup.py
@@ -27,7 +27,7 @@
         self.force_manifest = 1
         if (sys.platform != "win32" and 
             os.path.isdir('.git')):
-            assert os.system("git show-ref -s HEAD > .gitrev") == 0
+            assert os.system("git rev-parse --verify HEAD > .gitrev") == 0
         sdist_orig.run(self)
 add_command_class('sdist', sdist)