pre sync_stream.cc creation. Does not compile
diff --git a/test/cpp/qps/client_sync.cc b/test/cpp/qps/client_sync.cc
index 92fbf24..d93537b 100644
--- a/test/cpp/qps/client_sync.cc
+++ b/test/cpp/qps/client_sync.cc
@@ -41,6 +41,7 @@
 #include <vector>
 
 #include <gflags/gflags.h>
+#include <grpc++/channel.h>
 #include <grpc++/client_context.h>
 #include <grpc++/server.h>
 #include <grpc++/server_builder.h>