diff --git a/cpp/benchmarks/merge/merge_lists.cpp b/cpp/benchmarks/merge/merge_lists.cpp
index c145e5704616..543fb29f521b 100644
--- a/cpp/benchmarks/merge/merge_lists.cpp
+++ b/cpp/benchmarks/merge/merge_lists.cpp
@@ -14,7 +14,7 @@
 
 void nvbench_merge_list(nvbench::state& state)
 {
-  cuda::stream_ref stream;
+  cuda::stream_ref stream = cudf::get_default_stream();
 
   auto const input1 = create_lists_data(state);
   auto const sorted_input1 =
diff --git a/cpp/benchmarks/merge/merge_structs.cpp b/cpp/benchmarks/merge/merge_structs.cpp
index b4dfd24e9a1d..4905efb1c96a 100644
--- a/cpp/benchmarks/merge/merge_structs.cpp
+++ b/cpp/benchmarks/merge/merge_structs.cpp
@@ -14,7 +14,7 @@
 
 void nvbench_merge_struct(nvbench::state& state)
 {
-  cuda::stream_ref stream;
+  cuda::stream_ref stream = cudf::get_default_stream();
 
   auto const input1 = create_structs_data(state);
   auto const sorted_input1 =