diff --git a/internal/ceres/minimizer_test.cc b/internal/ceres/minimizer_test.cc
index 3de4abe..10fb9e5 100644
--- a/internal/ceres/minimizer_test.cc
+++ b/internal/ceres/minimizer_test.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
@@ -34,12 +34,10 @@
 #include "ceres/solver.h"
 #include "gtest/gtest.h"
 
-namespace ceres {
-namespace internal {
+namespace ceres::internal {
 
 class FakeIterationCallback : public IterationCallback {
  public:
-  virtual ~FakeIterationCallback() {}
   CallbackReturnType operator()(const IterationSummary& summary) final {
     return SOLVER_CONTINUE;
   }
@@ -62,7 +60,6 @@
 
 class AbortingIterationCallback : public IterationCallback {
  public:
-  virtual ~AbortingIterationCallback() {}
   CallbackReturnType operator()(const IterationSummary& summary) final {
     return SOLVER_ABORT;
   }
@@ -80,7 +77,6 @@
 
 class SucceedingIterationCallback : public IterationCallback {
  public:
-  virtual ~SucceedingIterationCallback() {}
   CallbackReturnType operator()(const IterationSummary& summary) final {
     return SOLVER_TERMINATE_SUCCESSFULLY;
   }
@@ -97,5 +93,4 @@
             "User callback returned SOLVER_TERMINATE_SUCCESSFULLY.");
 }
 
-}  // namespace internal
-}  // namespace ceres
+}  // namespace ceres::internal