diff --git a/test/benchmark_min_time_flag_iters_test.cc b/test/benchmark_min_time_flag_iters_test.cc
index eb9414ac..3de93a75 100644
--- a/test/benchmark_min_time_flag_iters_test.cc
+++ b/test/benchmark_min_time_flag_iters_test.cc
@@ -46,7 +46,7 @@ BENCHMARK(BM_MyBench);
 int main(int argc, char** argv) {
   // Make a fake argv and append the new --benchmark_min_time=<foo> to it.
   int fake_argc = argc + 1;
-  const char** fake_argv = new const char*[fake_argc];
+  const char** fake_argv = new const char*[static_cast<size_t>(fake_argc)];
   for (int i = 0; i < argc; ++i) fake_argv[i] = argv[i];
   fake_argv[argc] = "--benchmark_min_time=4x";
 
diff --git a/test/benchmark_min_time_flag_time_test.cc b/test/benchmark_min_time_flag_time_test.cc
index b172cccb..04a82eb9 100644
--- a/test/benchmark_min_time_flag_time_test.cc
+++ b/test/benchmark_min_time_flag_time_test.cc
@@ -71,7 +71,7 @@ BENCHMARK(BM_MyBench);
 int main(int argc, char** argv) {
   // Make a fake argv and append the new --benchmark_min_time=<foo> to it.
   int fake_argc = argc + 1;
-  const char** fake_argv = new const char*[fake_argc];
+  const char** fake_argv = new const char*[static_cast<size_t>(fake_argc)];
 
   for (int i = 0; i < argc; ++i) fake_argv[i] = argv[i];
 
diff --git a/test/perf_counters_gtest.cc b/test/perf_counters_gtest.cc
index e73ebc58..bb55aff7 100644
--- a/test/perf_counters_gtest.cc
+++ b/test/perf_counters_gtest.cc
@@ -169,8 +169,8 @@ TEST(PerfCountersTest, CreateExistingMeasurements) {
   std::vector<std::pair<std::string, double>> measurements;
 
   // Start all counters together to see if they hold
-  int max_counters = kMaxCounters;
-  for (int i = 0; i < kMaxCounters; ++i) {
+  size_t max_counters = kMaxCounters;
+  for (size_t i = 0; i < kMaxCounters; ++i) {
     auto& counter(*perf_counter_measurements[i]);
     EXPECT_EQ(counter.num_counters(), 1);
     if (!counter.Start()) {
@@ -182,13 +182,13 @@ TEST(PerfCountersTest, CreateExistingMeasurements) {
   ASSERT_GE(max_counters, kMinValidCounters);
 
   // Start all together
-  for (int i = 0; i < max_counters; ++i) {
+  for (size_t i = 0; i < max_counters; ++i) {
     auto& counter(*perf_counter_measurements[i]);
     EXPECT_TRUE(counter.Stop(measurements) || (i >= kMinValidCounters));
   }
 
   // Start/stop individually
-  for (int i = 0; i < max_counters; ++i) {
+  for (size_t i = 0; i < max_counters; ++i) {
     auto& counter(*perf_counter_measurements[i]);
     measurements.clear();
     counter.Start();