diff --git a/include/cuco/detail/open_addressing/open_addressing_ref_impl.cuh b/include/cuco/detail/open_addressing/open_addressing_ref_impl.cuh
index 92ad4fe3c..1c77c76be 100644
--- a/include/cuco/detail/open_addressing/open_addressing_ref_impl.cuh
+++ b/include/cuco/detail/open_addressing/open_addressing_ref_impl.cuh
@@ -976,7 +976,7 @@ class open_addressing_ref_impl {
    * @param callback Function to call on every element found
    */
   template <class ProbeKey, class Callback>
-  __device__ void for_each(ProbeKey const& key, Callback callback) const noexcept
+  __device__ void for_each(ProbeKey const& key, Callback&& callback) const noexcept
   {
     static_assert(cg_size == 1, "Non-CG operation is incompatible with the current probing scheme");
     auto probing_iter = this->probing_scheme_(key, this->storage_ref_.window_extent());
@@ -1027,7 +1027,7 @@ class open_addressing_ref_impl {
   template <class ProbeKey, class Callback>
   __device__ void for_each(cooperative_groups::thread_block_tile<cg_size> const& group,
                            ProbeKey const& key,
-                           Callback callback) const noexcept
+                           Callback&& callback) const noexcept
   {
     auto probing_iter = probing_scheme_(group, key, storage_ref_.window_extent());
 
diff --git a/include/cuco/detail/static_multiset/static_multiset_ref.inl b/include/cuco/detail/static_multiset/static_multiset_ref.inl
index d34586579..78c54b1b4 100644
--- a/include/cuco/detail/static_multiset/static_multiset_ref.inl
+++ b/include/cuco/detail/static_multiset/static_multiset_ref.inl
@@ -22,6 +22,8 @@
 
 #include <cooperative_groups.h>
 
+#include <utility>
+
 namespace cuco {
 
 template <typename Key,
@@ -481,11 +483,11 @@ class operator_impl<
    * @param callback Function to call on every element found
    */
   template <class ProbeKey, class Callback>
-  __device__ void for_each(ProbeKey const& key, Callback callback) const noexcept
+  __device__ void for_each(ProbeKey const& key, Callback&& callback) const noexcept
   {
     // CRTP: cast `this` to the actual ref type
     auto const& ref_ = static_cast<ref_type const&>(*this);
-    ref_.impl_.for_each(key, callback);
+    ref_.impl_.for_each(key, std::forward<Callback>(callback));
   }
 
   /**
@@ -509,11 +511,11 @@ class operator_impl<
   template <class ProbeKey, class Callback>
   __device__ void for_each(cooperative_groups::thread_block_tile<cg_size> const& group,
                            ProbeKey const& key,
-                           Callback callback) const noexcept
+                           Callback&& callback) const noexcept
   {
     // CRTP: cast `this` to the actual ref type
     auto const& ref_ = static_cast<ref_type const&>(*this);
-    ref_.impl_.for_each(group, key, callback);
+    ref_.impl_.for_each(group, key, std::forward<Callback>(callback));
   }
 };
 
diff --git a/tests/static_multiset/for_each_test.cu b/tests/static_multiset/for_each_test.cu
index e7ecece1e..b0cb81091 100644
--- a/tests/static_multiset/for_each_test.cu
+++ b/tests/static_multiset/for_each_test.cu
@@ -72,6 +72,7 @@ CUCO_KERNEL void for_each_check_cooperative(Ref ref,
     ref.for_each(tile, key, [&] __device__(auto const it) {
       if (ref.key_eq()(key, *it)) { thread_matches++; }
     });
+    tile.sync();
     auto const tile_matches =
       cooperative_groups::reduce(tile, thread_matches, cooperative_groups::plus<std::size_t>());
     if (tile_matches != multiplicity and tile.thread_rank() == 0) {