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