diff --git a/tiledb/libtiledb/domain.cc b/tiledb/libtiledb/domain.cc
index b5bd847c17..e94dc1727e 100644
--- a/tiledb/libtiledb/domain.cc
+++ b/tiledb/libtiledb/domain.cc
@@ -49,7 +49,7 @@ void init_domain(py::module& m) {
 
         .def_property_readonly(
             "_domain",
-            [](Dimension& dim) {
+            [](Dimension& dim) -> py::tuple {
                 switch (dim.type()) {
                     case TILEDB_UINT64: {
                         auto dom = dim.domain<uint64_t>();