diff --git a/src/benchmark.cc b/src/benchmark.cc
index 91984f73..5082716b 100644
--- a/src/benchmark.cc
+++ b/src/benchmark.cc
@@ -29,10 +29,10 @@
 #include <condition_variable>
 #include <cstdio>
 #include <cstdlib>
-#include <cstring>
 #include <fstream>
 #include <iostream>
 #include <memory>
+#include <string>
 #include <thread>
 
 #include "check.h"
@@ -46,7 +46,8 @@
 #include "re.h"
 #include "statistics.h"
 #include "string_util.h"
-#include "timers.h"
+#include "thread_manager.h"
+#include "thread_timer.h"
 
 DEFINE_bool(benchmark_list_tests, false,
             "Print a list of benchmarks. This option overrides all other "
@@ -110,113 +111,6 @@ namespace internal {
 
 void UseCharPointer(char const volatile*) {}
 
-class ThreadManager {
- public:
-  ThreadManager(int num_threads)
-      : alive_threads_(num_threads), start_stop_barrier_(num_threads) {}
-
-  Mutex& GetBenchmarkMutex() const RETURN_CAPABILITY(benchmark_mutex_) {
-    return benchmark_mutex_;
-  }
-
-  bool StartStopBarrier() EXCLUDES(end_cond_mutex_) {
-    return start_stop_barrier_.wait();
-  }
-
-  void NotifyThreadComplete() EXCLUDES(end_cond_mutex_) {
-    start_stop_barrier_.removeThread();
-    if (--alive_threads_ == 0) {
-      MutexLock lock(end_cond_mutex_);
-      end_condition_.notify_all();
-    }
-  }
-
-  void WaitForAllThreads() EXCLUDES(end_cond_mutex_) {
-    MutexLock lock(end_cond_mutex_);
-    end_condition_.wait(lock.native_handle(),
-                        [this]() { return alive_threads_ == 0; });
-  }
-
- public:
-  struct Result {
-    double real_time_used = 0;
-    double cpu_time_used = 0;
-    double manual_time_used = 0;
-    int64_t bytes_processed = 0;
-    int64_t items_processed = 0;
-    int complexity_n = 0;
-    std::string report_label_;
-    std::string error_message_;
-    bool has_error_ = false;
-    UserCounters counters;
-  };
-  GUARDED_BY(GetBenchmarkMutex()) Result results;
-
- private:
-  mutable Mutex benchmark_mutex_;
-  std::atomic<int> alive_threads_;
-  Barrier start_stop_barrier_;
-  Mutex end_cond_mutex_;
-  Condition end_condition_;
-};
-
-// Timer management class
-class ThreadTimer {
- public:
-  ThreadTimer() = default;
-
-  // Called by each thread
-  void StartTimer() {
-    running_ = true;
-    start_real_time_ = ChronoClockNow();
-    start_cpu_time_ = ThreadCPUUsage();
-  }
-
-  // Called by each thread
-  void StopTimer() {
-    CHECK(running_);
-    running_ = false;
-    real_time_used_ += ChronoClockNow() - start_real_time_;
-    // Floating point error can result in the subtraction producing a negative
-    // time. Guard against that.
-    cpu_time_used_ += std::max<double>(ThreadCPUUsage() - start_cpu_time_, 0);
-  }
-
-  // Called by each thread
-  void SetIterationTime(double seconds) { manual_time_used_ += seconds; }
-
-  bool running() const { return running_; }
-
-  // REQUIRES: timer is not running
-  double real_time_used() {
-    CHECK(!running_);
-    return real_time_used_;
-  }
-
-  // REQUIRES: timer is not running
-  double cpu_time_used() {
-    CHECK(!running_);
-    return cpu_time_used_;
-  }
-
-  // REQUIRES: timer is not running
-  double manual_time_used() {
-    CHECK(!running_);
-    return manual_time_used_;
-  }
-
- private:
-  bool running_ = false;        // Is the timer running
-  double start_real_time_ = 0;  // If running_
-  double start_cpu_time_ = 0;   // If running_
-
-  // Accumulated time so far (does not contain current slice if running_)
-  double real_time_used_ = 0;
-  double cpu_time_used_ = 0;
-  // Manually set iteration time. User sets this with SetIterationTime(seconds).
-  double manual_time_used_ = 0;
-};
-
 namespace {
 
 BenchmarkReporter::Run CreateRunReport(
diff --git a/src/thread_manager.h b/src/thread_manager.h
new file mode 100644
index 00000000..f9ee267d
--- /dev/null
+++ b/src/thread_manager.h
@@ -0,0 +1,62 @@
+#ifndef BENCHMARK_THREAD_MANAGER_H
+#define BENCHMARK_THREAD_MANAGER_H
+
+#include "mutex.h"
+
+namespace benchmark {
+namespace internal {
+
+class ThreadManager {
+ public:
+  ThreadManager(int num_threads)
+      : alive_threads_(num_threads), start_stop_barrier_(num_threads) {}
+
+  Mutex& GetBenchmarkMutex() const RETURN_CAPABILITY(benchmark_mutex_) {
+    return benchmark_mutex_;
+  }
+
+  bool StartStopBarrier() EXCLUDES(end_cond_mutex_) {
+    return start_stop_barrier_.wait();
+  }
+
+  void NotifyThreadComplete() EXCLUDES(end_cond_mutex_) {
+    start_stop_barrier_.removeThread();
+    if (--alive_threads_ == 0) {
+      MutexLock lock(end_cond_mutex_);
+      end_condition_.notify_all();
+    }
+  }
+
+  void WaitForAllThreads() EXCLUDES(end_cond_mutex_) {
+    MutexLock lock(end_cond_mutex_);
+    end_condition_.wait(lock.native_handle(),
+                        [this]() { return alive_threads_ == 0; });
+  }
+
+ public:
+  struct Result {
+    double real_time_used = 0;
+    double cpu_time_used = 0;
+    double manual_time_used = 0;
+    int64_t bytes_processed = 0;
+    int64_t items_processed = 0;
+    int complexity_n = 0;
+    std::string report_label_;
+    std::string error_message_;
+    bool has_error_ = false;
+    UserCounters counters;
+  };
+  GUARDED_BY(GetBenchmarkMutex()) Result results;
+
+ private:
+  mutable Mutex benchmark_mutex_;
+  std::atomic<int> alive_threads_;
+  Barrier start_stop_barrier_;
+  Mutex end_cond_mutex_;
+  Condition end_condition_;
+};
+
+}  // namespace internal
+}  // namespace benchmark
+
+#endif  // BENCHMARK_THREAD_MANAGER_H
diff --git a/src/thread_timer.h b/src/thread_timer.h
new file mode 100644
index 00000000..eaf108e0
--- /dev/null
+++ b/src/thread_timer.h
@@ -0,0 +1,69 @@
+#ifndef BENCHMARK_THREAD_TIMER_H
+#define BENCHMARK_THREAD_TIMER_H
+
+#include "check.h"
+#include "timers.h"
+
+namespace benchmark {
+namespace internal {
+
+class ThreadTimer {
+ public:
+  ThreadTimer() = default;
+
+  // Called by each thread
+  void StartTimer() {
+    running_ = true;
+    start_real_time_ = ChronoClockNow();
+    start_cpu_time_ = ThreadCPUUsage();
+  }
+
+  // Called by each thread
+  void StopTimer() {
+    CHECK(running_);
+    running_ = false;
+    real_time_used_ += ChronoClockNow() - start_real_time_;
+    // Floating point error can result in the subtraction producing a negative
+    // time. Guard against that.
+    cpu_time_used_ += std::max<double>(ThreadCPUUsage() - start_cpu_time_, 0);
+  }
+
+  // Called by each thread
+  void SetIterationTime(double seconds) { manual_time_used_ += seconds; }
+
+  bool running() const { return running_; }
+
+  // REQUIRES: timer is not running
+  double real_time_used() {
+    CHECK(!running_);
+    return real_time_used_;
+  }
+
+  // REQUIRES: timer is not running
+  double cpu_time_used() {
+    CHECK(!running_);
+    return cpu_time_used_;
+  }
+
+  // REQUIRES: timer is not running
+  double manual_time_used() {
+    CHECK(!running_);
+    return manual_time_used_;
+  }
+
+ private:
+  bool running_ = false;        // Is the timer running
+  double start_real_time_ = 0;  // If running_
+  double start_cpu_time_ = 0;   // If running_
+
+  // Accumulated time so far (does not contain current slice if running_)
+  double real_time_used_ = 0;
+  double cpu_time_used_ = 0;
+  // Manually set iteration time. User sets this with SetIterationTime(seconds).
+  double manual_time_used_ = 0;
+};
+
+}  // namespace internal
+}  // namespace benchmark
+
+#endif  // BENCHMARK_THREAD_TIMER_H