diff --git a/core/src/test_util/mod.rs b/core/src/test_util/mod.rs
index d9c7e6c5c..77ed44900 100644
--- a/core/src/test_util/mod.rs
+++ b/core/src/test_util/mod.rs
@@ -157,14 +157,14 @@ pub fn run_vdaf<
                         Role::Leader => vdaf
                             .leader_continued(
                                 curr_state.clone(),
-                                &aggregation_param,
+                                aggregation_param,
                                 last_peer_message,
                             )
                             .unwrap(),
                         Role::Helper => vdaf
                             .helper_continued(
                                 curr_state.clone(),
-                                &aggregation_param,
+                                aggregation_param,
                                 last_peer_message,
                             )
                             .unwrap(),