diff --git a/tests/test_unnamed_namespace_a.cpp b/tests/test_unnamed_namespace_a.cpp
index 26e9cb751..1204ccdc8 100644
--- a/tests/test_unnamed_namespace_a.cpp
+++ b/tests/test_unnamed_namespace_a.cpp
@@ -33,5 +33,11 @@ TEST_SUBMODULE(unnamed_namespace_a, m) {
         true;
 #else
         false;
+#endif
+    m.attr("defined___aarch64__") =
+#if defined(__aarch64__) || defined(_M_ARM64)
+        true;
+#else
+        false;
 #endif
 }
diff --git a/tests/test_unnamed_namespace_a.py b/tests/test_unnamed_namespace_a.py
index fabf1312a..18ce3a00d 100644
--- a/tests/test_unnamed_namespace_a.py
+++ b/tests/test_unnamed_namespace_a.py
@@ -5,7 +5,7 @@ import pytest
 from pybind11_tests import unnamed_namespace_a as m
 from pybind11_tests import unnamed_namespace_b as mb
 
-XFAIL_CONDITION = "not m.defined_WIN32_or__WIN32 and (m.defined___clang__ or m.defined__LIBCPP_VERSION)"
+XFAIL_CONDITION = "(not m.defined_WIN32_or__WIN32 and (m.defined___clang__ or m.defined__LIBCPP_VERSION)) or (m.defined_WIN32_or__WIN32 and m.defined___clang__ and m.defined___aarch64__)"
 XFAIL_REASON = "Known issues: https://github.com/pybind/pybind11/pull/4319"