diff --git a/include/pybind11/detail/descr.h b/include/pybind11/detail/descr.h
index 743bbf2ee..6a30b29bc 100644
--- a/include/pybind11/detail/descr.h
+++ b/include/pybind11/detail/descr.h
@@ -242,7 +242,8 @@ constexpr descr<N, Ts...> concat(const descr<N, Ts...> &descr) {
 template <size_t N1, size_t N2, typename... Ts1, typename... Ts2>
 constexpr descr<N1 + N2 + 2, Ts1..., Ts2...> operator,(const descr<N1, Ts1...> &a,
                                                        const descr<N2, Ts2...> &b) {
-    return a + const_name(", ") + b;
+    // Ensure that src_loc of existing descr is used.
+    return a + const_name(", ", src_loc{nullptr, 0}) + b;
 }
 
 template <size_t N, typename... Ts, typename... Args>