diff --git a/include/gtest/internal/custom/gtest.h b/include/gtest/internal/custom/gtest.h
new file mode 100644
index 00000000..c27412a8
--- /dev/null
+++ b/include/gtest/internal/custom/gtest.h
@@ -0,0 +1,41 @@
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Injection point for custom user configurations.
+// The following macros can be defined:
+//
+// GTEST_OS_STACK_TRACE_GETTER_  - The name of an implementation of
+//                                 OsStackTraceGetterInterface.
+//
+// ** Custom implementation starts here **
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_H_
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_H_
diff --git a/src/gtest-internal-inl.h b/src/gtest-internal-inl.h
index 6a7e2533..56c8a20c 100644
--- a/src/gtest-internal-inl.h
+++ b/src/gtest-internal-inl.h
@@ -433,6 +433,10 @@ class OsStackTraceGetterInterface {
   // CurrentStackTrace() will use to find and hide Google Test stack frames.
   virtual void UponLeavingGTest() = 0;
 
+  // This string is inserted in place of stack frames that are part of
+  // Google Test's implementation.
+  static const char* const kElidedFramesMarker;
+
  private:
   GTEST_DISALLOW_COPY_AND_ASSIGN_(OsStackTraceGetterInterface);
 };
@@ -440,26 +444,12 @@ class OsStackTraceGetterInterface {
 // A working implementation of the OsStackTraceGetterInterface interface.
 class OsStackTraceGetter : public OsStackTraceGetterInterface {
  public:
-  OsStackTraceGetter() : caller_frame_(NULL) {}
+  OsStackTraceGetter() {}
 
-  virtual string CurrentStackTrace(int max_depth, int skip_count)
-      GTEST_LOCK_EXCLUDED_(mutex_);
-
-  virtual void UponLeavingGTest() GTEST_LOCK_EXCLUDED_(mutex_);
-
-  // This string is inserted in place of stack frames that are part of
-  // Google Test's implementation.
-  static const char* const kElidedFramesMarker;
+  virtual string CurrentStackTrace(int max_depth, int skip_count);
+  virtual void UponLeavingGTest();
 
  private:
-  Mutex mutex_;  // protects all internal state
-
-  // We save the stack frame below the frame that calls user code.
-  // We do this because the address of the frame immediately below
-  // the user code changes between the call to UponLeavingGTest()
-  // and any calls to CurrentStackTrace() from within the user code.
-  void* caller_frame_;
-
   GTEST_DISALLOW_COPY_AND_ASSIGN_(OsStackTraceGetter);
 };
 
diff --git a/src/gtest.cc b/src/gtest.cc
index aa508bb2..1c5117d3 100644
--- a/src/gtest.cc
+++ b/src/gtest.cc
@@ -32,6 +32,7 @@
 // The Google C++ Testing Framework (Google Test)
 
 #include "gtest/gtest.h"
+#include "gtest/internal/custom/gtest.h"
 #include "gtest/gtest-spi.h"
 
 #include <ctype.h>
@@ -789,8 +790,12 @@ int UnitTestImpl::test_to_run_count() const {
 // CurrentOsStackTraceExceptTop(1), Foo() will be included in the
 // trace but Bar() and CurrentOsStackTraceExceptTop() won't.
 std::string UnitTestImpl::CurrentOsStackTraceExceptTop(int skip_count) {
-  (void)skip_count;
-  return "";
+  return os_stack_trace_getter()->CurrentStackTrace(
+      static_cast<int>(GTEST_FLAG(stack_trace_depth)),
+      skip_count + 1
+      // Skips the user-specified number of frames plus this function
+      // itself.
+      );  // NOLINT
 }
 
 // Returns the current time in milliseconds.
@@ -3833,26 +3838,15 @@ ScopedTrace::~ScopedTrace()
 
 // class OsStackTraceGetter
 
-// Returns the current OS stack trace as an std::string.  Parameters:
-//
-//   max_depth  - the maximum number of stack frames to be included
-//                in the trace.
-//   skip_count - the number of top frames to be skipped; doesn't count
-//                against max_depth.
-//
-string OsStackTraceGetter::CurrentStackTrace(int /* max_depth */,
-                                             int /* skip_count */)
-    GTEST_LOCK_EXCLUDED_(mutex_) {
+const char* const OsStackTraceGetterInterface::kElidedFramesMarker =
+    "... " GTEST_NAME_ " internal frames ...";
+
+string OsStackTraceGetter::CurrentStackTrace(int /*max_depth*/,
+                                             int /*skip_count*/) {
   return "";
 }
 
-void OsStackTraceGetter::UponLeavingGTest()
-    GTEST_LOCK_EXCLUDED_(mutex_) {
-}
-
-const char* const
-OsStackTraceGetter::kElidedFramesMarker =
-    "... " GTEST_NAME_ " internal frames ...";
+void OsStackTraceGetter::UponLeavingGTest() {}
 
 // A helper class that creates the premature-exit file in its
 // constructor and deletes the file in its destructor.
@@ -4907,7 +4901,11 @@ void UnitTestImpl::set_os_stack_trace_getter(
 // getter, and returns it.
 OsStackTraceGetterInterface* UnitTestImpl::os_stack_trace_getter() {
   if (os_stack_trace_getter_ == NULL) {
+#ifdef GTEST_OS_STACK_TRACE_GETTER_
+    os_stack_trace_getter_ = new GTEST_OS_STACK_TRACE_GETTER_;
+#else
     os_stack_trace_getter_ = new OsStackTraceGetter;
+#endif  // GTEST_OS_STACK_TRACE_GETTER_
   }
 
   return os_stack_trace_getter_;