diff --git a/include/scaluq/types.hpp b/include/scaluq/types.hpp
index c5cfa27..1f69e96 100644
--- a/include/scaluq/types.hpp
+++ b/include/scaluq/types.hpp
@@ -69,7 +69,7 @@ struct adl_serializer<::scaluq::StdComplex> {
 
 #ifdef SCALUQ_USE_NANOBIND
 #include <nanobind/nanobind.h>
-namespace scaluq {
+namespace scaluq::internal {
 namespace nb = nanobind;
 }
 #endif