diff --git a/examples/powell.cc b/examples/powell.cc
index c75ad24..a4ca1b7 100644
--- a/examples/powell.cc
+++ b/examples/powell.cc
@@ -1,5 +1,5 @@
 // Ceres Solver - A fast non-linear least squares minimizer
-// Copyright 2015 Google Inc. All rights reserved.
+// Copyright 2023 Google Inc. All rights reserved.
 // http://ceres-solver.org/
 //
 // Redistribution and use in source and binary forms, with or without
@@ -50,12 +50,6 @@
 #include "gflags/gflags.h"
 #include "glog/logging.h"
 
-using ceres::AutoDiffCostFunction;
-using ceres::CostFunction;
-using ceres::Problem;
-using ceres::Solve;
-using ceres::Solver;
-
 struct F1 {
   template <typename T>
   bool operator()(const T* const x1, const T* const x2, T* residual) const {
@@ -105,24 +99,24 @@
   double x3 = 0.0;
   double x4 = 1.0;
 
-  Problem problem;
-  // Add residual terms to the problem using the using the autodiff
+  ceres::Problem problem;
+  // Add residual terms to the problem using the autodiff
   // wrapper to get the derivatives automatically. The parameters, x1 through
   // x4, are modified in place.
   problem.AddResidualBlock(
-      new AutoDiffCostFunction<F1, 1, 1, 1>(new F1), NULL, &x1, &x2);
+      new ceres::AutoDiffCostFunction<F1, 1, 1, 1>(), nullptr, &x1, &x2);
   problem.AddResidualBlock(
-      new AutoDiffCostFunction<F2, 1, 1, 1>(new F2), NULL, &x3, &x4);
+      new ceres::AutoDiffCostFunction<F2, 1, 1, 1>(), nullptr, &x3, &x4);
   problem.AddResidualBlock(
-      new AutoDiffCostFunction<F3, 1, 1, 1>(new F3), NULL, &x2, &x3);
+      new ceres::AutoDiffCostFunction<F3, 1, 1, 1>(), nullptr, &x2, &x3);
   problem.AddResidualBlock(
-      new AutoDiffCostFunction<F4, 1, 1, 1>(new F4), NULL, &x1, &x4);
+      new ceres::AutoDiffCostFunction<F4, 1, 1, 1>(), nullptr, &x1, &x4);
 
-  Solver::Options options;
-  LOG_IF(
-      FATAL,
-      !ceres::StringToMinimizerType(FLAGS_minimizer, &options.minimizer_type))
-      << "Invalid minimizer: " << FLAGS_minimizer
+  ceres::Solver::Options options;
+  LOG_IF(FATAL,
+         !ceres::StringToMinimizerType(CERES_GET_FLAG(FLAGS_minimizer),
+                                       &options.minimizer_type))
+      << "Invalid minimizer: " << CERES_GET_FLAG(FLAGS_minimizer)
       << ", valid options are: trust_region and line_search.";
 
   options.max_num_iterations = 100;
@@ -138,8 +132,8 @@
   // clang-format on
 
   // Run the solver!
-  Solver::Summary summary;
-  Solve(options, &problem, &summary);
+  ceres::Solver::Summary summary;
+  ceres::Solve(options, &problem, &summary);
 
   std::cout << summary.FullReport() << "\n";
   // clang-format off