diff --git a/tensorflow/cc/training/queue_runner.cc b/tensorflow/cc/training/queue_runner.cc
index 1d23f9d87e2..87b696edc39 100644
--- a/tensorflow/cc/training/queue_runner.cc
+++ b/tensorflow/cc/training/queue_runner.cc
@@ -118,7 +118,7 @@ absl::Status QueueRunner::StartAndCollectCostGraph(
 
 absl::Status QueueRunner::Start(Session* sess, int wait_for) {
   counter_ = std::make_unique<BlockingCounter>(runs_);
-  for (const string& enqueue_op : enqueue_op_names_) {
+  for (const std::string& enqueue_op : enqueue_op_names_) {
     thread_pool_->Schedule(
         std::bind(&QueueRunner::Run, this, sess, enqueue_op));
   }
@@ -182,7 +182,7 @@ void QueueRunner::UpdateStatus(const absl::Status& status) {
   }
 }
 
-void QueueRunner::Run(Session* sess, const string& enqueue_op) {
+void QueueRunner::Run(Session* sess, const std::string& enqueue_op) {
   bool first_iteration = true;
   absl::Status status;
   while (status.ok()) {
@@ -245,7 +245,7 @@ void QueueRunner::SetRunArgumentsAndCostGraph(const RunOptions& run_options) {
   run_options_ = run_options;
 }
 
-absl::Status QueueRunner::RealRun(Session* sess, const string& op,
+absl::Status QueueRunner::RealRun(Session* sess, const std::string& op,
                                   bool update_costs) {
   absl::Status s;
   if (update_costs && cg_mu_) {
diff --git a/tensorflow/cc/training/queue_runner.h b/tensorflow/cc/training/queue_runner.h
index d5d6ca10a56..ffba8987c6d 100644
--- a/tensorflow/cc/training/queue_runner.h
+++ b/tensorflow/cc/training/queue_runner.h
@@ -97,7 +97,7 @@ class QueueRunner : public RunnerInterface {
   absl::Status Init(const QueueRunnerDef& queue_runner_def);
 
   // The Run function for each thread.
-  void Run(Session* sess, const string& enqueue_op);
+  void Run(Session* sess, const std::string& enqueue_op);
 
   // Updates the internal status; it only keeps OK or the first unexpected error
   // status.
@@ -112,12 +112,12 @@ class QueueRunner : public RunnerInterface {
 
   void SetRunArgumentsAndCostGraph(const RunOptions& run_options);
 
-  absl::Status RealRun(Session* sess, const string& op, bool update_costs);
+  absl::Status RealRun(Session* sess, const std::string& op, bool update_costs);
 
-  string queue_name_;
-  std::vector<string> enqueue_op_names_;
-  string close_op_name_;
-  string cancel_op_name_;
+  std::string queue_name_;
+  std::vector<std::string> enqueue_op_names_;
+  std::string close_op_name_;
+  std::string cancel_op_name_;
   // code::Code casted to int to avoid a hash function.
   std::unordered_set<int> queue_closed_exception_types_;