diff --git a/include/pybind11/numpy.h b/include/pybind11/numpy.h
index f64084e8..c7cbb9fd 100644
--- a/include/pybind11/numpy.h
+++ b/include/pybind11/numpy.h
@@ -940,9 +940,9 @@ struct format_descriptor<T, detail::enable_if_t<std::is_enum<T>::value>> {
 template <typename T>
 struct format_descriptor<T, detail::enable_if_t<detail::array_info<T>::is_array>> {
     static std::string format() {
-        using detail::_;
-        static constexpr auto extents = _("(") + detail::array_info<T>::extents + _(")");
-        return extents.text + format_descriptor<detail::remove_all_extents_t<T>>::format();
+        using namespace detail;
+        static constexpr auto extents = _("(") + array_info<T>::extents + _(")");
+        return extents.text + format_descriptor<remove_all_extents_t<T>>::format();
     }
 };