diff --git a/include/pybind11/detail/descr.h b/include/pybind11/detail/descr.h
index e4baa383b..e5a5a77e2 100644
--- a/include/pybind11/detail/descr.h
+++ b/include/pybind11/detail/descr.h
@@ -64,6 +64,10 @@ struct src_loc {
 
 #endif
 
+#ifdef PYBIND11_DETAIL_DESCR_SRC_LOC_ON
+namespace {
+#endif
+
 /* Concatenate type signatures at compile time */
 template <size_t N, typename... Ts>
 struct descr {
@@ -212,5 +216,9 @@ constexpr descr<N + 2, Ts...> type_descr(const descr<N, Ts...> &descr) {
     return const_name("{", src_loc{nullptr, 0}) + descr + const_name("}");
 }
 
+#ifdef PYBIND11_DETAIL_DESCR_SRC_LOC_ON
+} // namespace
+#endif
+
 PYBIND11_NAMESPACE_END(detail)
 PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
diff --git a/include/pybind11/detail/type_caster_odr_guard.h b/include/pybind11/detail/type_caster_odr_guard.h
index 4ae6d91fe..bfe28a79b 100644
--- a/include/pybind11/detail/type_caster_odr_guard.h
+++ b/include/pybind11/detail/type_caster_odr_guard.h
@@ -199,7 +199,7 @@ tu_local_no_data_always_false
           type_caster_odr_guard_impl(
               typeid(IntrinsicType),
               get_type_caster_source_file_line<TypeCasterType>::source_file_line.text,
-              get_type_caster_source_file_line<TypeCasterType>::source_file_line.sloc,
+              TypeCasterType::name.sloc,
               PYBIND11_DETAIL_TYPE_CASTER_ODR_GUARD_IMPL_THROW_DISABLED);
           return tu_local_no_data_always_false();
       }();