diff --git a/src/lib.rs b/src/lib.rs
index 2104b4e..8df0dca 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -110,7 +110,7 @@ pub use crate::request::RetryOptions;
 pub use crate::timestamp::{Timestamp, TimestampExt};
 #[doc(inline)]
 pub use crate::transaction::{
-    Client as TransactionClient, Snapshot, Transaction, TransactionOptions,
+    CheckLevel, Client as TransactionClient, Snapshot, Transaction, TransactionOptions,
 };
 #[doc(inline)]
 pub use config::Config;
diff --git a/src/pd/retry.rs b/src/pd/retry.rs
index d2a0da7..798d845 100644
--- a/src/pd/retry.rs
+++ b/src/pd/retry.rs
@@ -54,6 +54,8 @@ macro_rules! retry {
         let stats = pd_stats($tag);
         let mut last_err = Ok(());
         for _ in 0..LEADER_CHANGE_RETRY {
+            // use the block here to drop the guard of the read lock,
+            // otherwise `reconnect` will try to acquire the write lock and results in a deadlock
             let res = {
                 let $cluster = &$self.cluster.read().await.0;
                 let res = $call.await;
diff --git a/src/transaction/mod.rs b/src/transaction/mod.rs
index bf37880..d2eb03a 100644
--- a/src/transaction/mod.rs
+++ b/src/transaction/mod.rs
@@ -11,7 +11,7 @@
 pub use client::Client;
 pub(crate) use lock::{resolve_locks, HasLocks};
 pub use snapshot::Snapshot;
-pub use transaction::{Transaction, TransactionOptions};
+pub use transaction::{CheckLevel, Transaction, TransactionOptions};
 
 mod buffer;
 mod client;