diff --git a/googlemock/include/gmock/gmock-spec-builders.h b/googlemock/include/gmock/gmock-spec-builders.h
index c4c42b7c..445a3ed8 100644
--- a/googlemock/include/gmock/gmock-spec-builders.h
+++ b/googlemock/include/gmock/gmock-spec-builders.h
@@ -1530,7 +1530,7 @@ class FunctionMocker<R(Args...)> final : public UntypedFunctionMockerBase {
     UntypedOnCallSpecs specs_to_delete;
     untyped_on_call_specs_.swap(specs_to_delete);
 
-    g_gmock_mutex.Unlock();
+    g_gmock_mutex.unlock();
     for (UntypedOnCallSpecs::const_iterator it = specs_to_delete.begin();
          it != specs_to_delete.end(); ++it) {
       delete static_cast<const OnCallSpec<F>*>(*it);
@@ -1538,7 +1538,7 @@ class FunctionMocker<R(Args...)> final : public UntypedFunctionMockerBase {
 
     // Lock the mutex again, since the caller expects it to be locked when we
     // return.
-    g_gmock_mutex.Lock();
+    g_gmock_mutex.lock();
   }
 
   // Returns the result of invoking this mock function with the given
diff --git a/googlemock/src/gmock-spec-builders.cc b/googlemock/src/gmock-spec-builders.cc
index b681fee7..603ad7aa 100644
--- a/googlemock/src/gmock-spec-builders.cc
+++ b/googlemock/src/gmock-spec-builders.cc
@@ -436,9 +436,9 @@ bool UntypedFunctionMockerBase::VerifyAndClearExpectationsLocked()
   UntypedExpectations expectations_to_delete;
   untyped_expectations_.swap(expectations_to_delete);
 
-  g_gmock_mutex.Unlock();
+  g_gmock_mutex.unlock();
   expectations_to_delete.clear();
-  g_gmock_mutex.Lock();
+  g_gmock_mutex.lock();
 
   return expectations_met;
 }
diff --git a/googletest/include/gtest/internal/gtest-port.h b/googletest/include/gtest/internal/gtest-port.h
index 06a5a8e6..9bd41cd6 100644
--- a/googletest/include/gtest/internal/gtest-port.h
+++ b/googletest/include/gtest/internal/gtest-port.h
@@ -1385,9 +1385,9 @@ class GTEST_API_ Mutex {
   Mutex();
   ~Mutex();
 
-  void Lock();
+  void lock();
 
-  void Unlock();
+  void unlock();
 
   // Does nothing if the current thread holds the mutex. Otherwise, crashes
   // with high probability.
@@ -1424,9 +1424,9 @@ class GTEST_API_ Mutex {
 // "MutexLock l(&mu)".  Hence the typedef trick below.
 class GTestMutexLock {
  public:
-  explicit GTestMutexLock(Mutex* mutex) : mutex_(mutex) { mutex_->Lock(); }
+  explicit GTestMutexLock(Mutex* mutex) : mutex_(mutex) { mutex_->lock(); }
 
-  ~GTestMutexLock() { mutex_->Unlock(); }
+  ~GTestMutexLock() { mutex_->unlock(); }
 
  private:
   Mutex* const mutex_;
@@ -1641,14 +1641,14 @@ class ThreadLocal : public ThreadLocalBase {
 class MutexBase {
  public:
   // Acquires this mutex.
-  void Lock() {
+  void lock() {
     GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_lock(&mutex_));
     owner_ = pthread_self();
     has_owner_ = true;
   }
 
   // Releases this mutex.
-  void Unlock() {
+  void unlock() {
     // Since the lock is being released the owner_ field should no longer be
     // considered valid. We don't protect writing to has_owner_ here, as it's
     // the caller's responsibility to ensure that the current thread holds the
@@ -1716,9 +1716,9 @@ class Mutex : public MutexBase {
 // "MutexLock l(&mu)".  Hence the typedef trick below.
 class GTestMutexLock {
  public:
-  explicit GTestMutexLock(MutexBase* mutex) : mutex_(mutex) { mutex_->Lock(); }
+  explicit GTestMutexLock(MutexBase* mutex) : mutex_(mutex) { mutex_->lock(); }
 
-  ~GTestMutexLock() { mutex_->Unlock(); }
+  ~GTestMutexLock() { mutex_->unlock(); }
 
  private:
   MutexBase* const mutex_;
@@ -1864,8 +1864,8 @@ class GTEST_API_ ThreadLocal {
 class Mutex {
  public:
   Mutex() {}
-  void Lock() {}
-  void Unlock() {}
+  void lock() {}
+  void unlock() {}
   void AssertHeld() const {}
 };
 
diff --git a/googletest/src/gtest-port.cc b/googletest/src/gtest-port.cc
index 1038ad7b..490dbb57 100644
--- a/googletest/src/gtest-port.cc
+++ b/googletest/src/gtest-port.cc
@@ -320,13 +320,13 @@ Mutex::~Mutex() {
   }
 }
 
-void Mutex::Lock() {
+void Mutex::lock() {
   ThreadSafeLazyInit();
   ::EnterCriticalSection(critical_section_);
   owner_thread_id_ = ::GetCurrentThreadId();
 }
 
-void Mutex::Unlock() {
+void Mutex::unlock() {
   ThreadSafeLazyInit();
   // We don't protect writing to owner_thread_id_ here, as it's the
   // caller's responsibility to ensure that the current thread holds the
diff --git a/googletest/test/googletest-port-test.cc b/googletest/test/googletest-port-test.cc
index 9f05a019..975b2fc3 100644
--- a/googletest/test/googletest-port-test.cc
+++ b/googletest/test/googletest-port-test.cc
@@ -288,8 +288,8 @@ TEST(FormatCompilerIndependentFileLocationTest, FormatsUknownFileAndLine) {
     defined(GTEST_OS_OPENBSD) || defined(GTEST_OS_GNU_HURD)
 void* ThreadFunc(void* data) {
   internal::Mutex* mutex = static_cast<internal::Mutex*>(data);
-  mutex->Lock();
-  mutex->Unlock();
+  mutex->lock();
+  mutex->unlock();
   return nullptr;
 }