diff --git a/.gitignore b/.gitignore
index e13de17..5ca769f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 /target/
 
 Cargo.lock
+
+/.criterion/
diff --git a/benches/bench.rs b/benches/bench.rs
index 8347c78..22c1d40 100644
--- a/benches/bench.rs
+++ b/benches/bench.rs
@@ -8,12 +8,10 @@ use criterion::Criterion;
 use byte_ngram::*;
 
 fn criterion_benchmark(c: &mut Criterion) {
-    let data = String::from(
-        "Blackmail is such an ugly word. I prefer extortion. The 'x' makes it sound cool.",
-    );
+    let data = b"Blackmail is such an ugly word. I prefer extortion. The 'x' makes it sound cool.";
 
-    c.bench_function("from_slice", |b| b.iter(|| for _ in from_slice(data.as_bytes()) {}));
-    c.bench_function("ByteNgramReader", |b| b.iter(|| for _ in ByteNgramReader::new(data.as_bytes()) {}));
+    c.bench_function("from_slice", |b| b.iter(|| for _ in from_slice(&data[..]) {}));
+    c.bench_function("ByteNgramReader", |b| b.iter(|| for _ in ByteNgramReader::new(&data[..]) {}));
 }
 
 criterion_group!(benches, criterion_benchmark);