diff --git a/libcxx/benchmarks/CartesianBenchmarks.hpp b/libcxx/benchmarks/CartesianBenchmarks.h
rename from libcxx/benchmarks/CartesianBenchmarks.hpp
rename to libcxx/benchmarks/CartesianBenchmarks.h
diff --git a/libcxx/benchmarks/ContainerBenchmarks.hpp b/libcxx/benchmarks/ContainerBenchmarks.h
rename from libcxx/benchmarks/ContainerBenchmarks.hpp
rename to libcxx/benchmarks/ContainerBenchmarks.h
--- a/libcxx/benchmarks/ContainerBenchmarks.hpp
+++ b/libcxx/benchmarks/ContainerBenchmarks.h
@@ -7,12 +7,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef BENCHMARK_CONTAINER_BENCHMARKS_HPP
-#define BENCHMARK_CONTAINER_BENCHMARKS_HPP
+#ifndef BENCHMARK_CONTAINER_BENCHMARKS_H
+#define BENCHMARK_CONTAINER_BENCHMARKS_H
 
 #include <cassert>
 
-#include "Utilities.hpp"
+#include "Utilities.h"
 #include "benchmark/benchmark.h"
 
 namespace ContainerBenchmarks {
@@ -137,4 +137,4 @@
 
 } // end namespace ContainerBenchmarks
 
-#endif // BENCHMARK_CONTAINER_BENCHMARKS_HPP
+#endif // BENCHMARK_CONTAINER_BENCHMARKS_H
diff --git a/libcxx/benchmarks/GenerateInput.hpp b/libcxx/benchmarks/GenerateInput.h
rename from libcxx/benchmarks/GenerateInput.hpp
rename to libcxx/benchmarks/GenerateInput.h
--- a/libcxx/benchmarks/GenerateInput.hpp
+++ b/libcxx/benchmarks/GenerateInput.h
@@ -1,5 +1,5 @@
-#ifndef BENCHMARK_GENERATE_INPUT_HPP
-#define BENCHMARK_GENERATE_INPUT_HPP
+#ifndef BENCHMARK_GENERATE_INPUT_H
+#define BENCHMARK_GENERATE_INPUT_H
 
 #include <algorithm>
 #include <random>
@@ -141,4 +141,4 @@
 }
 
 
-#endif // BENCHMARK_GENERATE_INPUT_HPP
+#endif // BENCHMARK_GENERATE_INPUT_H
diff --git a/libcxx/benchmarks/Utilities.hpp b/libcxx/benchmarks/Utilities.h
rename from libcxx/benchmarks/Utilities.hpp
rename to libcxx/benchmarks/Utilities.h
--- a/libcxx/benchmarks/Utilities.hpp
+++ b/libcxx/benchmarks/Utilities.h
@@ -7,8 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef BENCHMARK_UTILITIES_HPP
-#define BENCHMARK_UTILITIES_HPP
+#ifndef BENCHMARK_UTILITIES_H
+#define BENCHMARK_UTILITIES_H
 
 #include <cassert>
 #include <type_traits>
@@ -30,4 +30,4 @@
 void DoNotOptimizeData(Container &c) { benchmark::DoNotOptimize(&c); }
 
 
-#endif // BENCHMARK_UTILITIES_HPP
+#endif // BENCHMARK_UTILITIES_H
diff --git a/libcxx/benchmarks/algorithms.bench.cpp b/libcxx/benchmarks/algorithms.bench.cpp
--- a/libcxx/benchmarks/algorithms.bench.cpp
+++ b/libcxx/benchmarks/algorithms.bench.cpp
@@ -7,8 +7,8 @@
 #include <utility>
 #include <vector>
 
-#include "CartesianBenchmarks.hpp"
-#include "GenerateInput.hpp"
+#include "CartesianBenchmarks.h"
+#include "GenerateInput.h"
 #include "benchmark/benchmark.h"
 #include "test_macros.h"
 
diff --git a/libcxx/benchmarks/algorithms.partition_point.bench.cpp b/libcxx/benchmarks/algorithms.partition_point.bench.cpp
--- a/libcxx/benchmarks/algorithms.partition_point.bench.cpp
+++ b/libcxx/benchmarks/algorithms.partition_point.bench.cpp
@@ -7,8 +7,8 @@
 
 #include "benchmark/benchmark.h"
 
-#include "CartesianBenchmarks.hpp"
-#include "GenerateInput.hpp"
+#include "CartesianBenchmarks.h"
+#include "GenerateInput.h"
 
 namespace {
 
diff --git a/libcxx/benchmarks/deque.bench.cpp b/libcxx/benchmarks/deque.bench.cpp
--- a/libcxx/benchmarks/deque.bench.cpp
+++ b/libcxx/benchmarks/deque.bench.cpp
@@ -11,8 +11,8 @@
 
 #include "benchmark/benchmark.h"
 
-#include "ContainerBenchmarks.hpp"
-#include "GenerateInput.hpp"
+#include "ContainerBenchmarks.h"
+#include "GenerateInput.h"
 
 using namespace ContainerBenchmarks;
 
diff --git a/libcxx/benchmarks/filesystem.bench.cpp b/libcxx/benchmarks/filesystem.bench.cpp
--- a/libcxx/benchmarks/filesystem.bench.cpp
+++ b/libcxx/benchmarks/filesystem.bench.cpp
@@ -1,5 +1,5 @@
 #include "benchmark/benchmark.h"
-#include "GenerateInput.hpp"
+#include "GenerateInput.h"
 #include "test_iterators.h"
 #include "filesystem_include.h"
 
diff --git a/libcxx/benchmarks/function.bench.cpp b/libcxx/benchmarks/function.bench.cpp
--- a/libcxx/benchmarks/function.bench.cpp
+++ b/libcxx/benchmarks/function.bench.cpp
@@ -11,7 +11,7 @@
 #include <memory>
 #include <string>
 
-#include "CartesianBenchmarks.hpp"
+#include "CartesianBenchmarks.h"
 #include "benchmark/benchmark.h"
 #include "test_macros.h"
 
diff --git a/libcxx/benchmarks/ordered_set.bench.cpp b/libcxx/benchmarks/ordered_set.bench.cpp
--- a/libcxx/benchmarks/ordered_set.bench.cpp
+++ b/libcxx/benchmarks/ordered_set.bench.cpp
@@ -14,7 +14,7 @@
 #include <string>
 #include <vector>
 
-#include "CartesianBenchmarks.hpp"
+#include "CartesianBenchmarks.h"
 #include "benchmark/benchmark.h"
 #include "test_macros.h"
 
diff --git a/libcxx/benchmarks/string.bench.cpp b/libcxx/benchmarks/string.bench.cpp
--- a/libcxx/benchmarks/string.bench.cpp
+++ b/libcxx/benchmarks/string.bench.cpp
@@ -3,8 +3,8 @@
 #include <new>
 #include <vector>
 
-#include "CartesianBenchmarks.hpp"
-#include "GenerateInput.hpp"
+#include "CartesianBenchmarks.h"
+#include "GenerateInput.h"
 #include "benchmark/benchmark.h"
 #include "test_macros.h"
 
diff --git a/libcxx/benchmarks/unordered_set_operations.bench.cpp b/libcxx/benchmarks/unordered_set_operations.bench.cpp
--- a/libcxx/benchmarks/unordered_set_operations.bench.cpp
+++ b/libcxx/benchmarks/unordered_set_operations.bench.cpp
@@ -7,8 +7,8 @@
 
 #include "benchmark/benchmark.h"
 
-#include "ContainerBenchmarks.hpp"
-#include "GenerateInput.hpp"
+#include "ContainerBenchmarks.h"
+#include "GenerateInput.h"
 #include "test_macros.h"
 
 using namespace ContainerBenchmarks;
diff --git a/libcxx/benchmarks/vector_operations.bench.cpp b/libcxx/benchmarks/vector_operations.bench.cpp
--- a/libcxx/benchmarks/vector_operations.bench.cpp
+++ b/libcxx/benchmarks/vector_operations.bench.cpp
@@ -6,8 +6,8 @@
 
 #include "benchmark/benchmark.h"
 
-#include "ContainerBenchmarks.hpp"
-#include "GenerateInput.hpp"
+#include "ContainerBenchmarks.h"
+#include "GenerateInput.h"
 
 using namespace ContainerBenchmarks;