diff --git a/cpp/include/raft/core/detail/copy.hpp b/cpp/include/raft/core/detail/copy.hpp
index 7ad5356b15..8c6f9d10ae 100644
--- a/cpp/include/raft/core/detail/copy.hpp
+++ b/cpp/include/raft/core/detail/copy.hpp
@@ -329,7 +329,7 @@ __device__ auto increment_indices(IdxType* indices,
  * parameters.
  */
 template <typename DstType, typename SrcType>
-RAFT_KERNEL mdspan_copyable_with_kernel_t<DstType, SrcType> mdspan_copy_kernel(DstType dst,
+mdspan_copyable_with_kernel_t<DstType, SrcType> RAFT_KERNEL mdspan_copy_kernel(DstType dst,
                                                                                SrcType src)
 {
   using config = mdspan_copyable<true, DstType, SrcType>;