diff --git a/src/test_util/mock_client.rs b/src/test_util/mock_client.rs
index e31a8cd..be143b6 100644
--- a/src/test_util/mock_client.rs
+++ b/src/test_util/mock_client.rs
@@ -163,3 +163,25 @@ impl Client for MockClient {
         Ok(())
     }
 }
+
+#[test]
+fn insert_share_works() {
+    use std::collections::HashSet;
+
+    let client = MockClient::default();
+    let share_ids: [_; 8] = std::array::from_fn(|_| ShareID::from(true));
+
+    for share_id in share_ids.as_ref() {
+        assert!(client.insert_share(share_id, MockShare::default()).is_ok());
+    }
+
+    assert_eq!(client.shares.borrow().len(), share_ids.len());
+
+    let sid_strings: HashSet<_> = share_ids.iter().map(ToString::to_string).collect();
+    let cli_strings: HashSet<_> = (client.shares.borrow())
+        .keys()
+        .map(ToString::to_string)
+        .collect();
+
+    assert_eq!(sid_strings, cli_strings);
+}