diff --git a/internal/ceres/block_jacobi_preconditioner_benchmark.cc b/internal/ceres/block_jacobi_preconditioner_benchmark.cc
index d2508c4..edd431d 100644
--- a/internal/ceres/block_jacobi_preconditioner_benchmark.cc
+++ b/internal/ceres/block_jacobi_preconditioner_benchmark.cc
@@ -63,7 +63,7 @@
   Preconditioner::Options preconditioner_options;
   ContextImpl context;
   preconditioner_options.context = &context;
-  preconditioner_options.num_threads = state.range(0);
+  preconditioner_options.num_threads = static_cast<int>(state.range(0));
   context.EnsureMinimumThreads(preconditioner_options.num_threads);
   BlockSparseJacobiPreconditioner p(preconditioner_options, *jacobian);
 
@@ -91,7 +91,7 @@
   Preconditioner::Options preconditioner_options;
   ContextImpl context;
   preconditioner_options.context = &context;
-  preconditioner_options.num_threads = state.range(0);
+  preconditioner_options.num_threads = static_cast<int>(state.range(0));
   context.EnsureMinimumThreads(preconditioner_options.num_threads);
   BlockCRSJacobiPreconditioner p(preconditioner_options, jacobian_crs);
 
@@ -124,7 +124,7 @@
   Preconditioner::Options preconditioner_options;
   ContextImpl context;
   preconditioner_options.context = &context;
-  preconditioner_options.num_threads = state.range(0);
+  preconditioner_options.num_threads = static_cast<int>(state.range(0));
   context.EnsureMinimumThreads(preconditioner_options.num_threads);
   BlockSparseJacobiPreconditioner p(preconditioner_options, *jacobian);
 
@@ -160,7 +160,7 @@
   Preconditioner::Options preconditioner_options;
   ContextImpl context;
   preconditioner_options.context = &context;
-  preconditioner_options.num_threads = state.range(0);
+  preconditioner_options.num_threads = static_cast<int>(state.range(0));
   context.EnsureMinimumThreads(preconditioner_options.num_threads);
   BlockCRSJacobiPreconditioner p(preconditioner_options, jacobian_crs);
 
diff --git a/internal/ceres/dense_linear_solver_benchmark.cc b/internal/ceres/dense_linear_solver_benchmark.cc
index a01e0d6..a5c529b 100644
--- a/internal/ceres/dense_linear_solver_benchmark.cc
+++ b/internal/ceres/dense_linear_solver_benchmark.cc
@@ -40,8 +40,8 @@
 template <ceres::DenseLinearAlgebraLibraryType kLibraryType,
           ceres::LinearSolverType kSolverType>
 static void BM_DenseSolver(benchmark::State& state) {
-  const int num_rows = state.range(0);
-  const int num_cols = state.range(1);
+  const int num_rows = static_cast<int>(state.range(0));
+  const int num_cols = static_cast<int>(state.range(1));
   DenseSparseMatrix jacobian(num_rows, num_cols);
   *jacobian.mutable_matrix() = Eigen::MatrixXd::Random(num_rows, num_cols);
   Eigen::VectorXd rhs = Eigen::VectorXd::Random(num_rows, 1);
diff --git a/internal/ceres/evaluation_benchmark.cc b/internal/ceres/evaluation_benchmark.cc
index be784c2..5dc1ef4 100644
--- a/internal/ceres/evaluation_benchmark.cc
+++ b/internal/ceres/evaluation_benchmark.cc
@@ -208,7 +208,7 @@
 static void Residuals(benchmark::State& state,
                       BALData* data,
                       ContextImpl* context) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
 
   Evaluator::Options options;
   options.linear_solver_type = SPARSE_NORMAL_CHOLESKY;
@@ -240,7 +240,7 @@
 static void ResidualsAndJacobian(benchmark::State& state,
                                  BALData* data,
                                  ContextImpl* context) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
 
   Evaluator::Options options;
   options.linear_solver_type = SPARSE_NORMAL_CHOLESKY;
@@ -271,7 +271,7 @@
 }
 
 static void Plus(benchmark::State& state, BALData* data, ContextImpl* context) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
 
   Evaluator::Options options;
   options.linear_solver_type = SPARSE_NORMAL_CHOLESKY;
@@ -300,7 +300,7 @@
                                            BALData* data,
                                            ContextImpl* context) {
   LinearSolver::Options options;
-  options.num_threads = state.range(0);
+  options.num_threads = static_cast<int>(state.range(0));
   options.elimination_groups.push_back(data->bal_problem->num_points());
   options.context = context;
   auto jacobian = data->PartitionedMatrixViewJacobian(options);
@@ -318,7 +318,7 @@
                                           BALData* data,
                                           ContextImpl* context) {
   LinearSolver::Options options;
-  options.num_threads = state.range(0);
+  options.num_threads = static_cast<int>(state.range(0));
   options.elimination_groups.push_back(data->bal_problem->num_points());
   options.context = context;
   auto jacobian = data->PartitionedMatrixViewJacobian(options);
@@ -336,7 +336,7 @@
                                            BALData* data,
                                            ContextImpl* context) {
   LinearSolver::Options options;
-  options.num_threads = state.range(0);
+  options.num_threads = static_cast<int>(state.range(0));
   options.elimination_groups.push_back(data->bal_problem->num_points());
   options.context = context;
   auto jacobian = data->PartitionedMatrixViewJacobian(options);
@@ -354,7 +354,7 @@
                                           BALData* data,
                                           ContextImpl* context) {
   LinearSolver::Options options;
-  options.num_threads = state.range(0);
+  options.num_threads = static_cast<int>(state.range(0));
   options.elimination_groups.push_back(data->bal_problem->num_points());
   options.context = context;
   auto jacobian = data->PartitionedMatrixViewJacobian(options);
@@ -372,7 +372,7 @@
                                       BALData* data,
                                       ContextImpl* context) {
   LinearSolver::Options options;
-  options.num_threads = state.range(0);
+  options.num_threads = static_cast<int>(state.range(0));
   options.elimination_groups.push_back(data->bal_problem->num_points());
   options.context = context;
   auto jacobian = data->PartitionedMatrixViewJacobian(options);
@@ -387,7 +387,7 @@
                                       BALData* data,
                                       ContextImpl* context) {
   LinearSolver::Options options;
-  options.num_threads = state.range(0);
+  options.num_threads = static_cast<int>(state.range(0));
   options.elimination_groups.push_back(data->bal_problem->num_points());
   options.context = context;
   auto jacobian = data->PartitionedMatrixViewJacobian(options);
@@ -402,7 +402,7 @@
                                    BALData* data,
                                    ContextImpl* context) {
   LinearSolver::Options options;
-  options.num_threads = state.range(0);
+  options.num_threads = static_cast<int>(state.range(0));
   options.elimination_groups.push_back(data->bal_problem->num_points());
   options.context = context;
   auto jacobian = data->ImplicitSchurComplementWithoutDiagonal(options);
@@ -419,7 +419,7 @@
                                  BALData* data,
                                  ContextImpl* context) {
   LinearSolver::Options options;
-  options.num_threads = state.range(0);
+  options.num_threads = static_cast<int>(state.range(0));
   options.elimination_groups.push_back(data->bal_problem->num_points());
   options.context = context;
 
@@ -436,7 +436,7 @@
 static void JacobianSquaredColumnNorm(benchmark::State& state,
                                       BALData* data,
                                       ContextImpl* context) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
 
   auto jacobian = data->BlockSparseJacobian(context);
 
@@ -451,7 +451,7 @@
 static void JacobianScaleColumns(benchmark::State& state,
                                  BALData* data,
                                  ContextImpl* context) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
 
   auto jacobian_const = data->BlockSparseJacobian(context);
   auto jacobian = const_cast<BlockSparseMatrix*>(jacobian_const);
@@ -466,7 +466,7 @@
 static void JacobianRightMultiplyAndAccumulate(benchmark::State& state,
                                                BALData* data,
                                                ContextImpl* context) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
 
   auto jacobian = data->BlockSparseJacobian(context);
 
@@ -483,7 +483,7 @@
 static void JacobianLeftMultiplyAndAccumulate(benchmark::State& state,
                                               BALData* data,
                                               ContextImpl* context) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
 
   auto jacobian = data->BlockSparseJacobian(context);
 
diff --git a/internal/ceres/invert_psd_matrix_benchmark.cc b/internal/ceres/invert_psd_matrix_benchmark.cc
index eb8deb1..d23e9f8 100644
--- a/internal/ceres/invert_psd_matrix_benchmark.cc
+++ b/internal/ceres/invert_psd_matrix_benchmark.cc
@@ -64,7 +64,7 @@
 static void BenchmarkDynamicallyInvertPSDMatrix(benchmark::State& state) {
   using MatrixType =
       typename EigenTypes<Eigen::Dynamic, Eigen::Dynamic>::Matrix;
-  const int size = state.range(0);
+  const int size = static_cast<int>(state.range(0));
   MatrixType input = MatrixType::Random(size, size);
   input += input.transpose() + MatrixType::Identity(size, size);
 
diff --git a/internal/ceres/parallel_vector_operations_benchmark.cc b/internal/ceres/parallel_vector_operations_benchmark.cc
index 7e523c3..6dd9a5b 100644
--- a/internal/ceres/parallel_vector_operations_benchmark.cc
+++ b/internal/ceres/parallel_vector_operations_benchmark.cc
@@ -46,7 +46,7 @@
 BENCHMARK(SetZero);
 
 static void SetZeroParallel(benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   ContextImpl context;
   context.EnsureMinimumThreads(num_threads);
 
@@ -70,7 +70,7 @@
 BENCHMARK(Negate);
 
 static void NegateParallel(benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   ContextImpl context;
   context.EnsureMinimumThreads(num_threads);
 
@@ -95,7 +95,7 @@
 BENCHMARK(Assign);
 
 static void AssignParallel(benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   ContextImpl context;
   context.EnsureMinimumThreads(num_threads);
 
@@ -121,7 +121,7 @@
 BENCHMARK(D2X);
 
 static void D2XParallel(benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   ContextImpl context;
   context.EnsureMinimumThreads(num_threads);
 
@@ -147,7 +147,7 @@
 BENCHMARK(DivideSqrt);
 
 static void DivideSqrtParallel(benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   ContextImpl context;
   context.EnsureMinimumThreads(num_threads);
 
@@ -176,7 +176,7 @@
 BENCHMARK(Clamp);
 
 static void ClampParallel(benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   ContextImpl context;
   context.EnsureMinimumThreads(num_threads);
 
@@ -204,7 +204,7 @@
 BENCHMARK(Norm);
 
 static void NormParallel(benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   ContextImpl context;
   context.EnsureMinimumThreads(num_threads);
 
@@ -231,7 +231,7 @@
 BENCHMARK(Dot);
 
 static void DotParallel(benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   ContextImpl context;
   context.EnsureMinimumThreads(num_threads);
 
@@ -261,7 +261,7 @@
 BENCHMARK(Axpby);
 
 static void AxpbyParallel(benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   ContextImpl context;
   context.EnsureMinimumThreads(num_threads);
 
diff --git a/internal/ceres/spmv_benchmark.cc b/internal/ceres/spmv_benchmark.cc
index 69df1ea..2a6e679 100644
--- a/internal/ceres/spmv_benchmark.cc
+++ b/internal/ceres/spmv_benchmark.cc
@@ -66,7 +66,7 @@
 
 static void BM_BlockSparseRightMultiplyAndAccumulateBA(
     benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   std::mt19937 prng;
   auto jacobian = CreateFakeBundleAdjustmentJacobian(
       kNumCameras, kNumPoints, kCameraSize, kPointSize, kVisibility, prng);
@@ -96,7 +96,7 @@
 
 static void BM_BlockSparseRightMultiplyAndAccumulateUnstructured(
     benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   BlockSparseMatrix::RandomMatrixOptions options;
   options.num_row_blocks = kNumRowBlocks;
   options.num_col_blocks = kNumColBlocks;
@@ -178,7 +178,7 @@
 BENCHMARK(BM_BlockSparseLeftMultiplyAndAccumulateUnstructured);
 
 static void BM_CRSRightMultiplyAndAccumulateBA(benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   std::mt19937 prng;
   auto bsm_jacobian = CreateFakeBundleAdjustmentJacobian(
       kNumCameras, kNumPoints, kCameraSize, kPointSize, kVisibility, prng);
@@ -213,7 +213,7 @@
 
 static void BM_CRSRightMultiplyAndAccumulateUnstructured(
     benchmark::State& state) {
-  const int num_threads = state.range(0);
+  const int num_threads = static_cast<int>(state.range(0));
   BlockSparseMatrix::RandomMatrixOptions options;
   options.num_row_blocks = kNumRowBlocks;
   options.num_col_blocks = kNumColBlocks;