diff --git a/googletest/include/gtest/internal/gtest-port.h b/googletest/include/gtest/internal/gtest-port.h
index 81f047bf..2c819c9f 100644
--- a/googletest/include/gtest/internal/gtest-port.h
+++ b/googletest/include/gtest/internal/gtest-port.h
@@ -107,6 +107,12 @@
 //   GTEST_CREATE_SHARED_LIBRARY
 //                            - Define to 1 when compiling Google Test itself
 //                              as a shared library.
+//   GTEST_DEFAULT_DEATH_TEST_STYLE
+//                            - The default value of --gtest_death_test_style.
+//                              The legacy default has been "fast" in the open
+//                              source version since 2008. The recommended value
+//                              is "threadsafe", and can be set in
+//                              custom/gtest-port.h.
 
 // Platform-indicating macros
 // --------------------------
@@ -974,6 +980,10 @@ using ::std::tuple_size;
 # define GTEST_API_
 #endif // GTEST_API_
 
+#ifndef GTEST_DEFAULT_DEATH_TEST_STYLE
+# define GTEST_DEFAULT_DEATH_TEST_STYLE  "fast"
+#endif  // GTEST_DEFAULT_DEATH_TEST_STYLE
+
 #ifdef __GNUC__
 // Ask the compiler to never inline a given function.
 # define GTEST_NO_INLINE_ __attribute__((noinline))
diff --git a/googletest/src/gtest-death-test.cc b/googletest/src/gtest-death-test.cc
index 852912b5..9ecab8f9 100644
--- a/googletest/src/gtest-death-test.cc
+++ b/googletest/src/gtest-death-test.cc
@@ -73,7 +73,11 @@ namespace testing {
 // Constants.
 
 // The default death test style.
-static const char kDefaultDeathTestStyle[] = "threadsafe";
+//
+// This is defined in internal/gtest-port.h as "fast", but can be overridden by
+// a definition in internal/custom/gtest-port.h. The recommended value, which is
+// used internally at Google, is "threadsafe".
+static const char kDefaultDeathTestStyle[] = GTEST_DEFAULT_DEATH_TEST_STYLE;
 
 GTEST_DEFINE_string_(
     death_test_style,
diff --git a/googletest/test/gtest_env_var_test.py b/googletest/test/gtest_env_var_test.py
index 2fe9cd5f..7af00cee 100755
--- a/googletest/test/gtest_env_var_test.py
+++ b/googletest/test/gtest_env_var_test.py
@@ -92,7 +92,7 @@ class GTestEnvVarTest(gtest_test_utils.TestCase):
     TestFlag('print_time', '0', '1')
     TestFlag('repeat', '999', '1')
     TestFlag('throw_on_failure', '1', '0')
-    TestFlag('death_test_style', 'fast', 'threadsafe')
+    TestFlag('death_test_style', 'threadsafe', 'fast')
     TestFlag('catch_exceptions', '0', '1')
 
     if IS_LINUX: