diff --git a/rayon-demo/src/mergesort/bench.rs b/rayon-demo/src/mergesort/bench.rs
index ad6a23d5d..a97c786c2 100644
--- a/rayon-demo/src/mergesort/bench.rs
+++ b/rayon-demo/src/mergesort/bench.rs
@@ -4,9 +4,9 @@ const BENCH_SIZE: usize = 250_000_000 / 512;
 
 fn bench_harness<F: FnMut(&mut [u32])>(mut f: F, b: &mut test::Bencher) {
     let base_vec = super::default_vec(BENCH_SIZE);
-    let mut sort_vec = vec![];
+    let mut sort_vec = base_vec.clone();
     b.iter(|| {
-        sort_vec = base_vec.clone();
+        sort_vec.clone_from(&base_vec);
         f(&mut sort_vec);
     });
     assert!(super::is_sorted(&mut sort_vec));
diff --git a/rayon-demo/src/quicksort/bench.rs b/rayon-demo/src/quicksort/bench.rs
index 5b4fc1e7b..231c8d1bb 100644
--- a/rayon-demo/src/quicksort/bench.rs
+++ b/rayon-demo/src/quicksort/bench.rs
@@ -6,9 +6,9 @@ const BENCH_SIZE: usize = 250_000_000 / 512;
 
 fn bench_harness<F: FnMut(&mut [u32])>(mut f: F, b: &mut test::Bencher) {
     let base_vec = super::default_vec(BENCH_SIZE);
-    let mut sort_vec = vec![];
+    let mut sort_vec = base_vec.clone();
     b.iter(|| {
-        sort_vec = base_vec.clone();
+        sort_vec.clone_from(&base_vec);
         f(&mut sort_vec);
     });
     assert!(super::is_sorted(&sort_vec));