diff --git a/tests/testutil.hpp b/tests/testutil.hpp
index 066a9286..0ab01bbd 100644
--- a/tests/testutil.hpp
+++ b/tests/testutil.hpp
@@ -56,6 +56,7 @@
 #       pragma warning(disable:4996)
 #   endif
 #else
+#   include <pthread.h>
 #   include <unistd.h>
 #   include <signal.h>
 #   include <stdlib.h>