diff --git a/Lib/test/test_faulthandler.py b/Lib/test/test_faulthandler.py
index 331dd2ec86e..977cb3928ba 100644
--- a/Lib/test/test_faulthandler.py
+++ b/Lib/test/test_faulthandler.py
@@ -174,6 +174,9 @@ def test_fatal_error(self):
             2,
             'xyz')
 
+    @unittest.skipIf(sys.platform.startswith('openbsd') and HAVE_THREADS,
+                     "Issue #12868: sigaltstack() doesn't work on "
+                     "OpenBSD if Python is compiled with pthread")
     @unittest.skipIf(not hasattr(faulthandler, '_stack_overflow'),
                      'need faulthandler._stack_overflow()')
     def test_stack_overflow(self):