diff --git a/lldb/packages/Python/lldbsuite/test/expression_command/ir-interpreter/TestIRInterpreter.py b/lldb/packages/Python/lldbsuite/test/expression_command/ir-interpreter/TestIRInterpreter.py
index 00d7eb26bf97..e40307d5321c 100644
--- a/lldb/packages/Python/lldbsuite/test/expression_command/ir-interpreter/TestIRInterpreter.py
+++ b/lldb/packages/Python/lldbsuite/test/expression_command/ir-interpreter/TestIRInterpreter.py
@@ -38,6 +38,7 @@ class IRInterpreterTestCase(TestBase):
         self.runCmd("run", RUN_SUCCEEDED)
 
     @add_test_categories(['pyapi'])
+    @expectedFailureAll(oslist=['windows'], bugnumber="21765")  # getpid() is POSIX, among other problems, see bug
     def test_ir_interpreter(self):
         self.build_and_run()