diff --git a/pyproject.toml b/pyproject.toml
index 291ea57..09808fc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,7 +14,7 @@ requires = [
     "wheel>=0.34.2",
     "cmake>=3.18",
     "scikit-build",
-    "nanobind",
+    "nanobind>=1.3",
     "ninja",
     "pcpp",
 ]
diff --git a/src/wrapper/wrap_isl.cpp b/src/wrapper/wrap_isl.cpp
index 4bb6d10..57af55c 100644
--- a/src/wrapper/wrap_isl.cpp
+++ b/src/wrapper/wrap_isl.cpp
@@ -107,7 +107,9 @@ NB_MODULE(_isl, m)
     .ENUM_VALUE(isl_stat_, ok)
     ;
 
-  py::enum_<isl_dim_type>(m, "dim_type")
+  // Arithmetic (i.e. export numerical values) to ensure that out == set, as on
+  // the C side.
+  py::enum_<isl_dim_type>(m, "dim_type", py::is_arithmetic())
     .ENUM_VALUE(isl_dim_, cst)
     .ENUM_VALUE(isl_dim_, param)
     .value("in_", isl_dim_in)