diff --git a/test/cpp/qps/client_async.cc b/test/cpp/qps/client_async.cc
index 06bc3ee9c259bdf2ffc7730a571b8f0972eef318..3c3814df2307448b095823e3d97e6ee0f8d6784f 100644
--- a/test/cpp/qps/client_async.cc
+++ b/test/cpp/qps/client_async.cc
@@ -150,6 +150,7 @@ class AsyncClient : public Client {
 					  const SimpleRequest&)> setup_ctx) :
       Client(config), channel_lock_(config.client_channels()),
       max_outstanding_per_channel_(config.outstanding_rpcs_per_channel()),
+      contexts_(config.client_channels()),
       channel_count_(config.client_channels()) {
 
     SetupLoadTest(config, config.async_client_threads());