--- a/tests/test_cached_property.py
+++ b/tests/test_cached_property.py
@@ -191,6 +191,7 @@
         self.assert_cached(check, 2)
         self.assert_cached(check, 2)
 
+    @unittest.skip("Gentoo Bug #638250")
     def test_threads_ttl_expiry(self):
         Check = CheckFactory(self.cached_property_factory(ttl=100000), threadsafe=True)
         check = Check()
