diff --git a/taskchampion/src/utils.rs b/taskchampion/src/utils.rs
index aafe6f010..6747b6cbd 100644
--- a/taskchampion/src/utils.rs
+++ b/taskchampion/src/utils.rs
@@ -8,7 +8,7 @@ pub(crate) struct Key(uuid::Bytes);
 
 impl From<&[u8]> for Key {
     fn from(bytes: &[u8]) -> Key {
-        Key(bytes.try_into().unwrap())
+        Key(bytes.try_into().expect("expected 16 bytes"))
     }
 }
 
@@ -37,3 +37,24 @@ impl AsRef<[u8]> for Key {
         &self.0[..]
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_from_bytes() {
+        let k: Key = (&[1u8, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16][..]).into();
+        let u: Uuid = k.into();
+        assert_eq!(
+            u,
+            Uuid::parse_str("01020304-0506-0708-090a-0b0c0d0e0f10").unwrap()
+        );
+    }
+
+    #[test]
+    #[should_panic]
+    fn test_from_bytes_bad_len() {
+        let _: Key = (&[1u8, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11][..]).into();
+    }
+}