diff --git a/postgresql-simple-queue.cabal b/postgresql-simple-queue.cabal
--- a/postgresql-simple-queue.cabal
+++ b/postgresql-simple-queue.cabal
@@ -1,5 +1,5 @@
 name:                postgresql-simple-queue
-version:             0.5.1.0
+version:             0.5.1.1
 synopsis: A PostgreSQL backed queue
 description:
  This module utilize PostgreSQL to implement a durable queue for efficently processing arbitrary payloads which can be represented as JSON.
diff --git a/src/Database/PostgreSQL/Simple/Queue.hs b/src/Database/PostgreSQL/Simple/Queue.hs
--- a/src/Database/PostgreSQL/Simple/Queue.hs
+++ b/src/Database/PostgreSQL/Simple/Queue.hs
@@ -235,7 +235,7 @@
     'Serializable' transaction.
 -}
 tryLock :: String -> Connection -> IO (Maybe Payload)
-tryLock schemaName conn = runDBTSerializable (tryLockDB schemaName) conn
+tryLock schemaName conn = runDBT (tryLockDB schemaName) ReadCommitted conn
 
 notifyPayload :: String -> Connection -> IO ()
 notifyPayload schemaName conn = do