diff --git a/benches/crypto_read.rs b/benches/crypto_read.rs
index c04e9d0..885178c 100644
--- a/benches/crypto_read.rs
+++ b/benches/crypto_read.rs
@@ -28,7 +28,8 @@ fn bench_read_1mb_chacha_file(c: &mut Criterion) {
             let mut file = file.try_clone().unwrap();
             file.seek(io::SeekFrom::Start(0)).unwrap();
             let mut reader = crypto::create_read(file, cipher, &key);
-            black_box(io::copy(&mut reader, &mut io::sink()).unwrap())
+            black_box(&reader);
+            io::copy(&mut reader, &mut io::sink()).unwrap();
         })
     });
 }
@@ -49,7 +50,8 @@ fn bench_read_1mb_aes_file(c: &mut Criterion) {
             rand::thread_rng().fill_bytes(cursor_random.get_mut());
             cursor_random.seek(io::SeekFrom::Start(0)).unwrap();
             io::copy(&mut cursor_random, &mut writer).unwrap();
-            black_box(writer.finish().unwrap())
+            black_box(&writer);
+            writer.finish().unwrap();
         })
     });
 }
@@ -75,7 +77,8 @@ fn bench_read_1mb_chacha_ram(c: &mut Criterion) {
             let mut cursor = cursor_write.clone();
             cursor.seek(io::SeekFrom::Start(0)).unwrap();
             let mut reader = crypto::create_read(cursor, cipher, &key);
-            black_box(io::copy(&mut reader, &mut io::sink()).unwrap())
+            black_box(&reader);
+            io::copy(&mut reader, &mut io::sink()).unwrap();
         })
     });
 }
@@ -101,7 +104,8 @@ fn bench_read_1mb_aes_ram(c: &mut Criterion) {
             let mut cursor = cursor_write.clone();
             cursor.seek(io::SeekFrom::Start(0)).unwrap();
             let mut reader = crypto::create_read(cursor, cipher, &key);
-            black_box(io::copy(&mut reader, &mut io::sink()).unwrap())
+            black_box(&reader);
+            io::copy(&mut reader, &mut io::sink()).unwrap();
         })
     });
 }