diff --git a/src/vec.rs b/src/vec.rs
index e1b91ecb47b67618aff18a1c740ae961bd673dc3..274b06c55bb7579165d6edbf2e279ebf66dfe898 100644
--- a/src/vec.rs
+++ b/src/vec.rs
@@ -236,15 +236,20 @@ mod tests {
     }
 
     #[test]
-    fn sanity() {
+    fn push_and_pop() {
         let mut v: Vec<i32, [i32; 4]> = Vec::new();
+        assert_eq!(v.len(), 0);
 
         assert_eq!(v.pop(), None);
+        assert_eq!(v.len(), 0);
 
         v.push(0).unwrap();
+        assert_eq!(v.len(), 1);
 
         assert_eq!(v.pop(), Some(0));
+        assert_eq!(v.len(), 0);
 
         assert_eq!(v.pop(), None);
+        assert_eq!(v.len(), 0);
     }
 }