diff --git a/tests/unistd_test.cpp b/tests/unistd_test.cpp
index 78b55c1..9ad3b6d 100644
--- a/tests/unistd_test.cpp
+++ b/tests/unistd_test.cpp
@@ -16,6 +16,7 @@
 
 #include <gtest/gtest.h>
 
+#include "DoNotOptimize.h"
 #include "SignalUtils.h"
 #include "utils.h"