diff --git a/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl_merge.h b/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl_merge.h
index 9c682966b12..cadff26a15d 100644
--- a/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl_merge.h
+++ b/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl_merge.h
@@ -82,7 +82,7 @@ __find_start_point(const _Rng1& __rng1, const _Rng2& __rng2, const _Index __i_el
 // to rng3 (starting from start3) in 'chunk' steps, but do not exceed the total size of the sequences (n1 and n2)
 template <typename _Rng1, typename _Rng2, typename _Rng3, typename _Index, typename _Compare>
 void
-__serial_merge(const _Rng1& __rng1, const _Rng2& __rng2, _Rng3& __rng3, _Index __start1, _Index __start2,
+__serial_merge(const _Rng1& __rng1, const _Rng2& __rng2, _Rng3& __rng3, const _Index __start1, const _Index __start2,
                const _Index __start3, const _Index __chunk, const _Index __n1, const _Index __n2, _Compare __comp)
 {
     const _Index __rng1_size = std::min<_Index>(__n1 > __start1 ? __n1 - __start1 : _Index{0}, __chunk);