diff --git a/Cargo.toml b/Cargo.toml
index 4f46a48..a814efe 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -52,11 +52,15 @@ version = "0.2"
 hex = "^0.3"
 bincode = "^0.9"
 criterion = "0.2"
+rand = "0.6"
 rand_os = "0.1"
 
 [[bench]]
 name = "ed25519_benchmarks"
 harness = false
+# This doesn't seem to work with criterion, cf. https://github.com/bheisler/criterion.rs/issues/344
+# For now, we have to bench by doing `cargo bench --features="batch"`.
+# required-features = ["batch"]
 
 [features]
 default = ["std", "u64_backend"]
diff --git a/benches/ed25519_benchmarks.rs b/benches/ed25519_benchmarks.rs
index 52cb597..e07eb61 100644
--- a/benches/ed25519_benchmarks.rs
+++ b/benches/ed25519_benchmarks.rs
@@ -22,7 +22,7 @@ mod ed25519_benches {
     use ed25519_dalek::Signature;
     use ed25519_dalek::verify_batch;
     use rand::thread_rng;
-    use rand::rngs::ThreadRng;
+    use rand::prelude::ThreadRng;
 
     fn sign(c: &mut Criterion) {
         let mut csprng: ThreadRng = thread_rng();