diff --git a/test/cpp/qps/client.h b/test/cpp/qps/client.h
index 0794a1569a6..b1d90aa9c44 100644
--- a/test/cpp/qps/client.h
+++ b/test/cpp/qps/client.h
@@ -369,12 +369,11 @@ class ClientImpl : public Client {
   ClientImpl(const ClientConfig& config,
              std::function<std::unique_ptr<StubType>(std::shared_ptr<Channel>)>
                  create_stub)
-      : cores_(gpr_cpu_num_cores()),
-        channels_(config.client_channels()),
-        create_stub_(create_stub) {
+      : cores_(gpr_cpu_num_cores()), create_stub_(create_stub) {
     for (int i = 0; i < config.client_channels(); i++) {
-      channels_[i].init(config.server_targets(i % config.server_targets_size()),
-                        config, create_stub_, i);
+      channels_.emplace_back(
+          config.server_targets(i % config.server_targets_size()), config,
+          create_stub_, i);
     }
 
     ClientRequestCreator<RequestType> create_req(&request_,
@@ -388,20 +387,11 @@ class ClientImpl : public Client {
 
   class ClientChannelInfo {
    public:
-    ClientChannelInfo() {}
-    ClientChannelInfo(const ClientChannelInfo& i) {
-      // The copy constructor is to satisfy old compilers
-      // that need it for using std::vector . It is only ever
-      // used for empty entries
-      GPR_ASSERT(!i.channel_ && !i.stub_);
-    }
-    void init(const grpc::string& target, const ClientConfig& config,
-              std::function<std::unique_ptr<StubType>(std::shared_ptr<Channel>)>
-                  create_stub,
-              int shard) {
-      // We have to use a 2-phase init like this with a default
-      // constructor followed by an initializer function to make
-      // old compilers happy with using this in std::vector
+    ClientChannelInfo(
+        const grpc::string& target, const ClientConfig& config,
+        std::function<std::unique_ptr<StubType>(std::shared_ptr<Channel>)>
+            create_stub,
+        int shard) {
       ChannelArguments args;
       args.SetInt("shard_to_ensure_no_subchannel_merges", shard);
       set_channel_args(config, &args);
diff --git a/test/cpp/qps/interarrival.h b/test/cpp/qps/interarrival.h
index c6e417985a8..1fa310c2091 100644
--- a/test/cpp/qps/interarrival.h
+++ b/test/cpp/qps/interarrival.h
@@ -21,7 +21,7 @@
 
 #include <chrono>
 #include <cmath>
-#include <cstdlib>
+#include <random>
 #include <vector>
 
 #include <grpc++/support/config.h>
@@ -75,13 +75,13 @@ class InterarrivalTimer {
  public:
   InterarrivalTimer() {}
   void init(const RandomDistInterface& r, int threads, int entries = 1000000) {
+    std::random_device devrand;
+    std::mt19937_64 generator(devrand());
+    std::uniform_real_distribution<double> rando(0, 1);
     for (int i = 0; i < entries; i++) {
-      // rand is the only choice that is portable across POSIX and Windows
-      // and that supports new and old compilers
-      const double uniform_0_1 =
-          static_cast<double>(rand()) / static_cast<double>(RAND_MAX);
       random_table_.push_back(
-          static_cast<int64_t>(1e9 * r.transform(uniform_0_1)));
+          static_cast<int64_t>(1e9 * r.transform(rando(generator))));
+      ;
     }
     // Now set up the thread positions
     for (int i = 0; i < threads; i++) {