diff --git a/include/gtest/gtest-param-test.h b/include/gtest/gtest-param-test.h
index 9a1d8a62..038f9ba7 100644
--- a/include/gtest/gtest-param-test.h
+++ b/include/gtest/gtest-param-test.h
@@ -1406,9 +1406,26 @@ internal::CartesianProductHolder10<Generator1, Generator2, Generator3,
       GTEST_TEST_CLASS_NAME_(test_case_name, test_name)::AddToRegistry(); \
   void GTEST_TEST_CLASS_NAME_(test_case_name, test_name)::TestBody()
 
-# define INSTANTIATE_TEST_CASE_P(prefix, test_case_name, generator) \
+// The optional last argument to INSTANTIATE_TEST_CASE_P allows the user
+// to specify a function or functor that generates custom test name suffixes
+// based on the test parameters. The function should accept one argument of
+// type testing::TestParamInfo<class ParamType>, and return std::string.
+//
+// testing::PrintToStringParamName is a builtin test suffix generator that
+// returns the value of testing::PrintToString(GetParam()). It does not work
+// for std::string or C strings.
+//
+// Note: test names must be non-empty, unique, and may only contain ASCII
+// alphanumeric characters or underscore.
+
+# define INSTANTIATE_TEST_CASE_P(prefix, test_case_name, generator, ...) \
   ::testing::internal::ParamGenerator<test_case_name::ParamType> \
       gtest_##prefix##test_case_name##_EvalGenerator_() { return generator; } \
+  ::std::string gtest_##prefix##test_case_name##_EvalGenerateName_( \
+      const ::testing::TestParamInfo<test_case_name::ParamType>& info) { \
+    return ::testing::internal::GetParamNameGen<test_case_name::ParamType> \
+        (__VA_ARGS__)(info); \
+  } \
   int gtest_##prefix##test_case_name##_dummy_ GTEST_ATTRIBUTE_UNUSED_ = \
       ::testing::UnitTest::GetInstance()->parameterized_test_registry(). \
           GetTestCasePatternHolder<test_case_name>(\
@@ -1417,6 +1434,7 @@ internal::CartesianProductHolder10<Generator1, Generator2, Generator3,
                   __FILE__, __LINE__))->AddTestCaseInstantiation(\
                       #prefix, \
                       &gtest_##prefix##test_case_name##_EvalGenerator_, \
+                      &gtest_##prefix##test_case_name##_EvalGenerateName_, \
                       __FILE__, __LINE__)
 
 }  // namespace testing
diff --git a/include/gtest/gtest-param-test.h.pump b/include/gtest/gtest-param-test.h.pump
index 45896502..3078d6d2 100644
--- a/include/gtest/gtest-param-test.h.pump
+++ b/include/gtest/gtest-param-test.h.pump
@@ -472,9 +472,26 @@ internal::CartesianProductHolder$i<$for j, [[Generator$j]]> Combine(
       GTEST_TEST_CLASS_NAME_(test_case_name, test_name)::AddToRegistry(); \
   void GTEST_TEST_CLASS_NAME_(test_case_name, test_name)::TestBody()
 
-# define INSTANTIATE_TEST_CASE_P(prefix, test_case_name, generator) \
+// The optional last argument to INSTANTIATE_TEST_CASE_P allows the user
+// to specify a function or functor that generates custom test name suffixes
+// based on the test parameters. The function should accept one argument of
+// type testing::TestParamInfo<class ParamType>, and return std::string.
+//
+// testing::PrintToStringParamName is a builtin test suffix generator that
+// returns the value of testing::PrintToString(GetParam()).
+//
+// Note: test names must be non-empty, unique, and may only contain ASCII
+// alphanumeric characters or underscore. Because PrintToString adds quotes
+// to std::string and C strings, it won't work for these types.
+
+# define INSTANTIATE_TEST_CASE_P(prefix, test_case_name, generator, ...) \
   ::testing::internal::ParamGenerator<test_case_name::ParamType> \
       gtest_##prefix##test_case_name##_EvalGenerator_() { return generator; } \
+  ::std::string gtest_##prefix##test_case_name##_EvalGenerateName_( \
+      const ::testing::TestParamInfo<test_case_name::ParamType>& info) { \
+    return ::testing::internal::GetParamNameGen<test_case_name::ParamType> \
+        (__VA_ARGS__)(info); \
+  } \
   int gtest_##prefix##test_case_name##_dummy_ GTEST_ATTRIBUTE_UNUSED_ = \
       ::testing::UnitTest::GetInstance()->parameterized_test_registry(). \
           GetTestCasePatternHolder<test_case_name>(\
@@ -483,6 +500,7 @@ internal::CartesianProductHolder$i<$for j, [[Generator$j]]> Combine(
                   __FILE__, __LINE__))->AddTestCaseInstantiation(\
                       #prefix, \
                       &gtest_##prefix##test_case_name##_EvalGenerator_, \
+                      &gtest_##prefix##test_case_name##_EvalGenerateName_, \
                       __FILE__, __LINE__)
 
 }  // namespace testing
diff --git a/include/gtest/internal/gtest-param-util.h b/include/gtest/internal/gtest-param-util.h
index efb2b945..5ffeaa4b 100644
--- a/include/gtest/internal/gtest-param-util.h
+++ b/include/gtest/internal/gtest-param-util.h
@@ -34,7 +34,10 @@
 #ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
 #define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
 
+#include <ctype.h>
+
 #include <iterator>
+#include <set>
 #include <utility>
 #include <vector>
 
@@ -49,6 +52,27 @@
 #if GTEST_HAS_PARAM_TEST
 
 namespace testing {
+
+// Input to a parameterized test name generator, describing a test parameter.
+// Consists of the parameter value and the integer parameter index.
+template <class ParamType>
+struct TestParamInfo {
+  TestParamInfo(const ParamType& a_param, size_t an_index) :
+    param(a_param),
+    index(an_index) {}
+  ParamType param;
+  size_t index;
+};
+
+// A builtin parameterized test name generator which returns the result of
+// testing::PrintToString.
+struct PrintToStringParamName {
+  template <class ParamType>
+  std::string operator()(const TestParamInfo<ParamType>& info) const {
+    return PrintToString(info.param);
+  }
+};
+
 namespace internal {
 
 // INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
@@ -345,6 +369,37 @@ class ValuesInIteratorRangeGenerator : public ParamGeneratorInterface<T> {
   const ContainerType container_;
 };  // class ValuesInIteratorRangeGenerator
 
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Default parameterized test name generator, returns a string containing the
+// integer test parameter index.
+template <class ParamType>
+std::string DefaultParamName(const TestParamInfo<ParamType>& info) {
+  Message name_stream;
+  name_stream << info.index;
+  return name_stream.GetString();
+}
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Parameterized test name overload helpers, which help the
+// INSTANTIATE_TEST_CASE_P macro choose between the default parameterized
+// test name generator and user param name generator.
+template <class ParamType, class ParamNameGenFunctor>
+ParamNameGenFunctor GetParamNameGen(ParamNameGenFunctor func) {
+  return func;
+}
+
+template <class ParamType>
+struct ParamNameGenFunc {
+  typedef std::string Type(const TestParamInfo<ParamType>&);
+};
+
+template <class ParamType>
+typename ParamNameGenFunc<ParamType>::Type *GetParamNameGen() {
+  return DefaultParamName;
+}
+
 // INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
 //
 // Stores a parameter value and later creates tests parameterized with that
@@ -449,6 +504,7 @@ class ParameterizedTestCaseInfo : public ParameterizedTestCaseInfoBase {
   typedef typename TestCase::ParamType ParamType;
   // A function that returns an instance of appropriate generator type.
   typedef ParamGenerator<ParamType>(GeneratorCreationFunc)();
+  typedef typename ParamNameGenFunc<ParamType>::Type ParamNameGeneratorFunc;
 
   explicit ParameterizedTestCaseInfo(
       const char* name, CodeLocation code_location)
@@ -475,9 +531,11 @@ class ParameterizedTestCaseInfo : public ParameterizedTestCaseInfoBase {
   // about a generator.
   int AddTestCaseInstantiation(const string& instantiation_name,
                                GeneratorCreationFunc* func,
-                               const char* /* file */,
-                               int /* line */) {
-    instantiations_.push_back(::std::make_pair(instantiation_name, func));
+                               ParamNameGeneratorFunc* name_func,
+                               const char* file,
+                               int line) {
+    instantiations_.push_back(
+        InstantiationInfo(instantiation_name, func, name_func, file, line));
     return 0;  // Return value used only to run this method in namespace scope.
   }
   // UnitTest class invokes this method to register tests in this test case
@@ -492,20 +550,39 @@ class ParameterizedTestCaseInfo : public ParameterizedTestCaseInfoBase {
       for (typename InstantiationContainer::iterator gen_it =
                instantiations_.begin(); gen_it != instantiations_.end();
                ++gen_it) {
-        const string& instantiation_name = gen_it->first;
-        ParamGenerator<ParamType> generator((*gen_it->second)());
+        const string& instantiation_name = gen_it->name;
+        ParamGenerator<ParamType> generator((*gen_it->generator)());
+        ParamNameGeneratorFunc* name_func = gen_it->name_func;
+        const char* file = gen_it->file;
+        int line = gen_it->line;
 
         string test_case_name;
         if ( !instantiation_name.empty() )
           test_case_name = instantiation_name + "/";
         test_case_name += test_info->test_case_base_name;
 
-        int i = 0;
+        size_t i = 0;
+        std::set<std::string> test_param_names;
         for (typename ParamGenerator<ParamType>::iterator param_it =
                  generator.begin();
              param_it != generator.end(); ++param_it, ++i) {
           Message test_name_stream;
-          test_name_stream << test_info->test_base_name << "/" << i;
+
+          std::string param_name = name_func(
+              TestParamInfo<ParamType>(*param_it, i));
+
+          GTEST_CHECK_(IsValidParamName(param_name))
+              << "Parameterized test name '" << param_name
+              << "' is invalid, in " << file
+              << " line " << line << std::endl;
+
+          GTEST_CHECK_(test_param_names.count(param_name) == 0)
+              << "Duplicate parameterized test name '" << param_name
+              << "', in " << file << " line " << line << std::endl;
+
+          test_param_names.insert(param_name);
+
+          test_name_stream << test_info->test_base_name << "/" << param_name;
           MakeAndRegisterTestInfo(
               test_case_name.c_str(),
               test_name_stream.GetString().c_str(),
@@ -537,10 +614,42 @@ class ParameterizedTestCaseInfo : public ParameterizedTestCaseInfoBase {
     const scoped_ptr<TestMetaFactoryBase<ParamType> > test_meta_factory;
   };
   typedef ::std::vector<linked_ptr<TestInfo> > TestInfoContainer;
-  // Keeps pairs of <Instantiation name, Sequence generator creation function>
-  // received from INSTANTIATE_TEST_CASE_P macros.
-  typedef ::std::vector<std::pair<string, GeneratorCreationFunc*> >
-      InstantiationContainer;
+  // Records data received from INSTANTIATE_TEST_CASE_P macros:
+  //  <Instantiation name, Sequence generator creation function,
+  //     Name generator function, Source file, Source line>
+  struct InstantiationInfo {
+      InstantiationInfo(const std::string &name_in,
+                        GeneratorCreationFunc* generator_in,
+                        ParamNameGeneratorFunc* name_func_in,
+                        const char* file_in,
+                        int line_in)
+          : name(name_in),
+            generator(generator_in),
+            name_func(name_func_in),
+            file(file_in),
+            line(line_in) {}
+
+      std::string name;
+      GeneratorCreationFunc* generator;
+      ParamNameGeneratorFunc* name_func;
+      const char* file;
+      int line;
+  };
+  typedef ::std::vector<InstantiationInfo> InstantiationContainer;
+
+  static bool IsValidParamName(const std::string& name) {
+    // Check for empty string
+    if (name.empty())
+      return false;
+
+    // Check for invalid characters
+    for (std::string::size_type index = 0; index < name.size(); ++index) {
+      if (!isalnum(name[index]) && name[index] != '_')
+        return false;
+    }
+
+    return true;
+  }
 
   const string test_case_name_;
   CodeLocation code_location_;
diff --git a/test/gtest-param-test_test.cc b/test/gtest-param-test_test.cc
index cc1dc65f..8b278bb9 100644
--- a/test/gtest-param-test_test.cc
+++ b/test/gtest-param-test_test.cc
@@ -809,6 +809,157 @@ TEST_P(NamingTest, TestsReportCorrectNamesAndParameters) {
 
 INSTANTIATE_TEST_CASE_P(ZeroToFiveSequence, NamingTest, Range(0, 5));
 
+// Tests that user supplied custom parameter names are working correctly.
+// Runs the test with a builtin helper method which uses PrintToString,
+// as well as a custom function and custom functor to ensure all possible
+// uses work correctly.
+class CustomFunctorNamingTest : public TestWithParam<std::string> {};
+TEST_P(CustomFunctorNamingTest, CustomTestNames) {}
+
+struct CustomParamNameFunctor {
+  std::string operator()(const ::testing::TestParamInfo<std::string>& info) {
+    return info.param;
+  }
+};
+
+INSTANTIATE_TEST_CASE_P(CustomParamNameFunctor,
+                        CustomFunctorNamingTest,
+                        Values(std::string("FunctorName")),
+                        CustomParamNameFunctor());
+
+INSTANTIATE_TEST_CASE_P(AllAllowedCharacters,
+                        CustomFunctorNamingTest,
+                        Values("abcdefghijklmnopqrstuvwxyz",
+                               "ABCDEFGHIJKLMNOPQRSTUVWXYZ",
+                               "01234567890_"),
+                        CustomParamNameFunctor());
+
+inline std::string CustomParamNameFunction(
+    const ::testing::TestParamInfo<std::string>& info) {
+  return info.param;
+}
+
+class CustomFunctionNamingTest : public TestWithParam<std::string> {};
+TEST_P(CustomFunctionNamingTest, CustomTestNames) {}
+
+INSTANTIATE_TEST_CASE_P(CustomParamNameFunction,
+                        CustomFunctionNamingTest,
+                        Values(std::string("FunctionName")),
+                        CustomParamNameFunction);
+
+#if GTEST_LANG_CXX11
+
+// Test custom naming with a lambda
+
+class CustomLambdaNamingTest : public TestWithParam<std::string> {};
+TEST_P(CustomLambdaNamingTest, CustomTestNames) {}
+
+INSTANTIATE_TEST_CASE_P(CustomParamNameLambda,
+                        CustomLambdaNamingTest,
+                        Values(std::string("LambdaName")),
+                        [](const ::testing::TestParamInfo<std::string>& info) {
+                          return info.param;
+                        });
+
+#endif  // GTEST_LANG_CXX11
+
+TEST(CustomNamingTest, CheckNameRegistry) {
+  ::testing::UnitTest* unit_test = ::testing::UnitTest::GetInstance();
+  std::set<std::string> test_names;
+  for (int case_num = 0;
+       case_num < unit_test->total_test_case_count();
+       ++case_num) {
+    const ::testing::TestCase* test_case = unit_test->GetTestCase(case_num);
+    for (int test_num = 0;
+         test_num < test_case->total_test_count();
+         ++test_num) {
+      const ::testing::TestInfo* test_info = test_case->GetTestInfo(test_num);
+      test_names.insert(std::string(test_info->name()));
+    }
+  }
+  EXPECT_EQ(1u, test_names.count("CustomTestNames/FunctorName"));
+  EXPECT_EQ(1u, test_names.count("CustomTestNames/FunctionName"));
+#if GTEST_LANG_CXX11
+  EXPECT_EQ(1u, test_names.count("CustomTestNames/LambdaName"));
+#endif  // GTEST_LANG_CXX11
+}
+
+// Test a numeric name to ensure PrintToStringParamName works correctly.
+
+class CustomIntegerNamingTest : public TestWithParam<int> {};
+
+TEST_P(CustomIntegerNamingTest, TestsReportCorrectNames) {
+  const ::testing::TestInfo* const test_info =
+     ::testing::UnitTest::GetInstance()->current_test_info();
+  Message test_name_stream;
+  test_name_stream << "TestsReportCorrectNames/" << GetParam();
+  EXPECT_STREQ(test_name_stream.GetString().c_str(), test_info->name());
+}
+
+INSTANTIATE_TEST_CASE_P(PrintToString,
+                        CustomIntegerNamingTest,
+                        Range(0, 5),
+                        ::testing::PrintToStringParamName());
+
+// Test a custom struct with PrintToString.
+
+struct CustomStruct {
+  explicit CustomStruct(int value) : x(value) {}
+  int x;
+};
+
+std::ostream& operator<<(std::ostream& stream, const CustomStruct& val) {
+  stream << val.x;
+  return stream;
+}
+
+class CustomStructNamingTest : public TestWithParam<CustomStruct> {};
+
+TEST_P(CustomStructNamingTest, TestsReportCorrectNames) {
+  const ::testing::TestInfo* const test_info =
+     ::testing::UnitTest::GetInstance()->current_test_info();
+  Message test_name_stream;
+  test_name_stream << "TestsReportCorrectNames/" << GetParam();
+  EXPECT_STREQ(test_name_stream.GetString().c_str(), test_info->name());
+}
+
+INSTANTIATE_TEST_CASE_P(PrintToString,
+                        CustomStructNamingTest,
+                        Values(CustomStruct(0), CustomStruct(1)),
+                        ::testing::PrintToStringParamName());
+
+// Test that using a stateful parameter naming function works as expected.
+
+struct StatefulNamingFunctor {
+  StatefulNamingFunctor() : sum(0) {}
+  std::string operator()(const ::testing::TestParamInfo<int>& info) {
+    int value = info.param + sum;
+    sum += info.param;
+    return ::testing::PrintToString(value);
+  }
+  int sum;
+};
+
+class StatefulNamingTest : public ::testing::TestWithParam<int> {
+ protected:
+  StatefulNamingTest() : sum_(0) {}
+  int sum_;
+};
+
+TEST_P(StatefulNamingTest, TestsReportCorrectNames) {
+  const ::testing::TestInfo* const test_info =
+     ::testing::UnitTest::GetInstance()->current_test_info();
+  sum_ += GetParam();
+  Message test_name_stream;
+  test_name_stream << "TestsReportCorrectNames/" << sum_;
+  EXPECT_STREQ(test_name_stream.GetString().c_str(), test_info->name());
+}
+
+INSTANTIATE_TEST_CASE_P(StatefulNamingFunctor,
+                        StatefulNamingTest,
+                        Range(0, 5),
+                        StatefulNamingFunctor());
+
 // Class that cannot be streamed into an ostream.  It needs to be copyable
 // (and, in case of MSVC, also assignable) in order to be a test parameter
 // type.  Its default copy constructor and assignment operator do exactly
diff --git a/test/gtest_output_test_.cc b/test/gtest_output_test_.cc
index a619459c..1070a9f2 100644
--- a/test/gtest_output_test_.cc
+++ b/test/gtest_output_test_.cc
@@ -755,6 +755,32 @@ TEST(ExpectFatalFailureTest, FailsWhenStatementThrows) {
 
 #endif  // GTEST_HAS_EXCEPTIONS
 
+// This #ifdef block tests the output of value-parameterized tests.
+
+#if GTEST_HAS_PARAM_TEST
+
+std::string ParamNameFunc(const testing::TestParamInfo<std::string>& info) {
+  return info.param;
+}
+
+class ParamTest : public testing::TestWithParam<std::string> {
+};
+
+TEST_P(ParamTest, Success) {
+  EXPECT_EQ("a", GetParam());
+}
+
+TEST_P(ParamTest, Failure) {
+  EXPECT_EQ("b", GetParam()) << "Expected failure";
+}
+
+INSTANTIATE_TEST_CASE_P(PrintingStrings,
+                        ParamTest,
+                        testing::Values(std::string("a")),
+                        ParamNameFunc);
+
+#endif  // GTEST_HAS_PARAM_TEST
+
 // This #ifdef block tests the output of typed tests.
 #if GTEST_HAS_TYPED_TEST
 
diff --git a/test/gtest_output_test_golden_lin.txt b/test/gtest_output_test_golden_lin.txt
index da541700..7fff8530 100644
--- a/test/gtest_output_test_golden_lin.txt
+++ b/test/gtest_output_test_golden_lin.txt
@@ -7,7 +7,7 @@ Expected: true
 gtest_output_test_.cc:#: Failure
 Value of: 3
 Expected: 2
-[==========] Running 64 tests from 28 test cases.
+[==========] Running 66 tests from 29 test cases.
 [----------] Global test environment set-up.
 FooEnvironment::SetUp() called.
 BarEnvironment::SetUp() called.
@@ -601,6 +601,16 @@ Value of: GetParam()
   Actual: 2
 Expected: 1
 [  FAILED  ] PrintingFailingParams/FailingParamTest.Fails/0, where GetParam() = 2
+[----------] 2 tests from PrintingStrings/ParamTest
+[ RUN      ] PrintingStrings/ParamTest.Success/a
+[       OK ] PrintingStrings/ParamTest.Success/a
+[ RUN      ] PrintingStrings/ParamTest.Failure/a
+gtest_output_test_.cc:#: Failure
+Value of: GetParam()
+  Actual: "a"
+Expected: "b"
+Expected failure
+[  FAILED  ] PrintingStrings/ParamTest.Failure/a, where GetParam() = "a"
 [----------] Global test environment tear-down
 BarEnvironment::TearDown() called.
 gtest_output_test_.cc:#: Failure
@@ -610,9 +620,9 @@ FooEnvironment::TearDown() called.
 gtest_output_test_.cc:#: Failure
 Failed
 Expected fatal failure.
-[==========] 64 tests from 28 test cases ran.
-[  PASSED  ] 21 tests.
-[  FAILED  ] 43 tests, listed below:
+[==========] 66 tests from 29 test cases ran.
+[  PASSED  ] 22 tests.
+[  FAILED  ] 44 tests, listed below:
 [  FAILED  ] NonfatalFailureTest.EscapesStringOperands
 [  FAILED  ] NonfatalFailureTest.DiffForLongStrings
 [  FAILED  ] FatalFailureTest.FatalFailureInSubroutine
@@ -656,8 +666,9 @@ Expected fatal failure.
 [  FAILED  ] ExpectFailureWithThreadsTest.ExpectNonFatalFailure
 [  FAILED  ] ScopedFakeTestPartResultReporterTest.InterceptOnlyCurrentThread
 [  FAILED  ] PrintingFailingParams/FailingParamTest.Fails/0, where GetParam() = 2
+[  FAILED  ] PrintingStrings/ParamTest.Failure/a, where GetParam() = "a"
 
-43 FAILED TESTS
+44 FAILED TESTS
   YOU HAVE 1 DISABLED TEST
 
 Note: Google Test filter = FatalFailureTest.*:LoggingTest.*