diff --git a/test/complexity_test.cc b/test/complexity_test.cc
index 8cf17f41d..5f930e11c 100644
--- a/test/complexity_test.cc
+++ b/test/complexity_test.cc
@@ -2,6 +2,7 @@
 #include <cassert>
 #include <cmath>
 #include <cstdlib>
+#include <string>
 #include <vector>
 
 #include "benchmark/benchmark.h"
diff --git a/test/internal_threading_test.cc b/test/internal_threading_test.cc
index c57bf44b0..d20931a83 100644
--- a/test/internal_threading_test.cc
+++ b/test/internal_threading_test.cc
@@ -2,6 +2,7 @@
 #undef NDEBUG
 
 #include <chrono>
+#include <ratio>
 #include <thread>
 
 #include "../src/timers.h"
diff --git a/test/locale_impermeability_test.cc b/test/locale_impermeability_test.cc
index e2dd6cfd9..ec2d4d277 100644
--- a/test/locale_impermeability_test.cc
+++ b/test/locale_impermeability_test.cc
@@ -1,7 +1,6 @@
 #undef NDEBUG
 #include <cassert>
-#include <cmath>
-#include <cstdlib>
+#include <locale>
 
 #include "benchmark/benchmark.h"
 #include "output_test.h"
diff --git a/test/output_test_helper.cc b/test/output_test_helper.cc
index 43a1bfde8..a4303d208 100644
--- a/test/output_test_helper.cc
+++ b/test/output_test_helper.cc
@@ -480,7 +480,7 @@ void RunOutputTests(int argc, char* argv[]) {
 BENCHMARK_RESTORE_DEPRECATED_WARNING
 
 int SubstrCnt(const std::string& haystack, const std::string& pat) {
-  if (pat.length() == 0) {
+  if (pat.empty()) {
     return 0;
   }
   int count = 0;
diff --git a/test/templated_fixture_method_test.cc b/test/templated_fixture_method_test.cc
index 06fc7d83e..2a7ee9c0d 100644
--- a/test/templated_fixture_method_test.cc
+++ b/test/templated_fixture_method_test.cc
@@ -1,6 +1,5 @@
 
 #include <cassert>
-#include <memory>
 
 #include "benchmark/benchmark.h"