diff --git a/googletest/test/googletest-listener-test.cc b/googletest/test/googletest-listener-test.cc
index d7c47c214..f7882a479 100644
--- a/googletest/test/googletest-listener-test.cc
+++ b/googletest/test/googletest-listener-test.cc
@@ -32,6 +32,7 @@
 // This file verifies Google Test event listeners receive events at the
 // right times.
 
+#include <iterator>
 #include <string>
 #include <vector>
 
@@ -498,8 +499,7 @@ int main(int argc, char** argv) {
                                          "1st.OnTestProgramEnd"};
 #endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
-  VerifyResults(events, expected_events,
-                sizeof(expected_events) / sizeof(expected_events[0]));
+  VerifyResults(events, expected_events, std::size(expected_events));
 
   // We need to check manually for ad hoc test failures that happen after
   // RUN_ALL_TESTS finishes.
diff --git a/googletest/test/googletest-output-test_.cc b/googletest/test/googletest-output-test_.cc
index e3560c018..175aa61cd 100644
--- a/googletest/test/googletest-output-test_.cc
+++ b/googletest/test/googletest-output-test_.cc
@@ -36,6 +36,7 @@
 #include <stdlib.h>
 
 #include <algorithm>
+#include <iterator>
 #include <string>
 
 #include "gtest/gtest-spi.h"
@@ -149,7 +150,7 @@ TEST(LoggingTest, InterleavingLoggingAndAssertions) {
   static const int a[4] = {3, 9, 2, 6};
 
   printf("(expecting 2 failures on (3) >= (a[i]))\n");
-  for (int i = 0; i < static_cast<int>(sizeof(a) / sizeof(*a)); i++) {
+  for (int i = 0; i < static_cast<int>(std::size(a)); i++) {
     printf("i == %d\n", i);
     EXPECT_GE(3, a[i]);
   }
diff --git a/googletest/test/googletest-param-test-test.cc b/googletest/test/googletest-param-test-test.cc
index 10d429c9a..78a1a22ab 100644
--- a/googletest/test/googletest-param-test-test.cc
+++ b/googletest/test/googletest-param-test-test.cc
@@ -39,6 +39,7 @@
 #include <cstdint>
 #include <functional>
 #include <iostream>
+#include <iterator>
 #include <list>
 #include <set>
 #include <sstream>
@@ -737,10 +738,7 @@ const int test_generation_params[] = {36, 42, 72};
 
 class TestGenerationTest : public TestWithParam<int> {
  public:
-  enum {
-    PARAMETER_COUNT =
-        sizeof(test_generation_params) / sizeof(test_generation_params[0])
-  };
+  enum { PARAMETER_COUNT = std::size(test_generation_params) };
 
   typedef TestGenerationEnvironment<PARAMETER_COUNT> Environment;
 
diff --git a/googletest/test/googletest-printers-test.cc b/googletest/test/googletest-printers-test.cc
index 7d7e933e2..0b11f8e4a 100644
--- a/googletest/test/googletest-printers-test.cc
+++ b/googletest/test/googletest-printers-test.cc
@@ -39,6 +39,7 @@
 #include <deque>
 #include <forward_list>
 #include <functional>
+#include <iterator>
 #include <limits>
 #include <list>
 #include <map>
@@ -1784,7 +1785,7 @@ TEST(IsValidUTF8Test, IllFormedUTF8) {
       // too.
       {"\xEE\x80\x80", "\"\\xEE\\x80\\x80\"\n    As Text: \"\""}};
 
-  for (int i = 0; i < int(sizeof(kTestdata) / sizeof(kTestdata[0])); ++i) {
+  for (int i = 0; i < int(std::size(kTestdata)); ++i) {
     EXPECT_PRINT_TO_STRING_(kTestdata[i][0], kTestdata[i][1]);
   }
 }
diff --git a/googletest/test/gtest_unittest.cc b/googletest/test/gtest_unittest.cc
index 081a6e3ce..d759f800e 100644
--- a/googletest/test/gtest_unittest.cc
+++ b/googletest/test/gtest_unittest.cc
@@ -33,6 +33,8 @@
 
 #include "gtest/gtest.h"
 
+#include <iterator>
+
 // Verifies that the command line flag variables can be accessed in
 // code once "gtest.h" has been #included.
 // Do not move it after other gtest #includes.
@@ -5853,9 +5855,8 @@ class ParseFlagsTest : public Test {
   // to specify the array sizes.
 
 #define GTEST_TEST_PARSING_FLAGS_(argv1, argv2, expected, should_print_help) \
-  TestParsingFlags(sizeof(argv1) / sizeof(*argv1) - 1, argv1,                \
-                   sizeof(argv2) / sizeof(*argv2) - 1, argv2, expected,      \
-                   should_print_help)
+  TestParsingFlags(std::size(argv1) - 1, argv1, std::size(argv2) - 1, argv2, \
+                   expected, should_print_help)
 };
 
 // Tests parsing an empty command line.