diff --git a/test/cpp/qps/client.h b/test/cpp/qps/client.h
index 6a822e35c78..92e77eed9b2 100644
--- a/test/cpp/qps/client.h
+++ b/test/cpp/qps/client.h
@@ -253,7 +253,7 @@ class Client {
 
     void ThreadFunc() {
       for (;;) {
-	// lock since the thread should only be doing one thing at a time
+        // lock since the thread should only be doing one thing at a time
         std::lock_guard<std::mutex> g(mu_);
         // run the loop body
         const bool thread_still_ok = client_->ThreadFunc(&histogram_, idx_);