diff --git a/aos/testing/prevent_exit.cc b/aos/testing/prevent_exit.cc
index 8624c93..b640fe7 100644
--- a/aos/testing/prevent_exit.cc
+++ b/aos/testing/prevent_exit.cc
@@ -1,23 +1,20 @@
 #include "aos/testing/prevent_exit.h"
 
-#include <stdlib.h>
 #include <unistd.h>
 
+#include <cstdlib>
+
 #include "glog/logging.h"
 
 namespace aos {
 namespace testing {
 namespace {
 
-void TerminateExitHandler() {
-  _exit(EXIT_SUCCESS);
-}
+void TerminateExitHandler() { _exit(EXIT_SUCCESS); }
 
 }  // namespace
 
-void PreventExit() {
-  CHECK_EQ(atexit(TerminateExitHandler), 0);
-}
+void PreventExit() { CHECK_EQ(atexit(TerminateExitHandler), 0); }
 
 }  // namespace testing
 }  // namespace aos
diff --git a/aos/testing/random_seed.cc b/aos/testing/random_seed.cc
index 9e7136f..8f26d07 100644
--- a/aos/testing/random_seed.cc
+++ b/aos/testing/random_seed.cc
@@ -1,6 +1,6 @@
 #include "aos/testing/random_seed.h"
 
-#include <stdlib.h>
+#include <cstdlib>
 
 namespace aos {
 namespace testing {
diff --git a/aos/testing/test_logging.cc b/aos/testing/test_logging.cc
index 74e5790..d0cea26 100644
--- a/aos/testing/test_logging.cc
+++ b/aos/testing/test_logging.cc
@@ -1,16 +1,13 @@
 #include "aos/testing/test_logging.h"
 
-#include <stdio.h>
-
+#include <cstdio>
 #include <vector>
 
-#include "gtest/gtest.h"
-
 #include "absl/base/call_once.h"
-
 #include "aos/logging/implementations.h"
 #include "aos/stl_mutex/stl_mutex.h"
 #include "aos/thread_local.h"
+#include "gtest/gtest.h"
 
 using ::aos::logging::LogMessage;