diff --git a/src/test_cases.rs b/src/test_cases.rs
index 3cd008e..a915766 100644
--- a/src/test_cases.rs
+++ b/src/test_cases.rs
@@ -1,15 +1,19 @@
 use crate::Segmenter;
 
 /// Run a segmenter against the built-in test cases
-pub fn run(segmenter: Segmenter) {
+pub fn run(segmenter: &Segmenter) {
     for test in TEST_CASES.iter().copied() {
-        let mut out = Vec::new();
-        segmenter.segment(&test.join(""), &mut out);
-        let cmp = out.iter().map(|s| &*s).collect::<Vec<_>>();
-        assert_eq!(cmp, test);
+        assert_segments(segmenter, test);
     }
 }
 
+pub fn assert_segments(segmenter: &Segmenter, s: &[&str]) {
+    let mut out = Vec::new();
+    segmenter.segment(&s.join(""), &mut out);
+    let cmp = out.iter().map(|s| &*s).collect::<Vec<_>>();
+    assert_eq!(cmp, s);
+}
+
 /// Built-in test cases
 ///
 /// These are exposed so that you can test with different data sources.
diff --git a/src/test_data.rs b/src/test_data.rs
index 63a4954..bd86c1d 100644
--- a/src/test_data.rs
+++ b/src/test_data.rs
@@ -9,7 +9,7 @@ use super::Segmenter;
 
 #[test]
 fn test_data() {
-    crate::test_cases::run(segmenter());
+    crate::test_cases::run(&segmenter());
 }
 
 pub fn segmenter() -> Segmenter {