diff --git a/src/benchmarks/match.cpp b/src/benchmarks/match.cpp
index 321fad386..d14882519 100644
--- a/src/benchmarks/match.cpp
+++ b/src/benchmarks/match.cpp
@@ -13,14 +13,14 @@
 #include <boost/assert.hpp>
 
 #include <boost/optional/optional.hpp>
+#include <cstdlib>
 #include <exception>
 #include <iostream>
+#include <optional>
 #include <stdexcept>
 #include <string>
 #include <utility>
 
-#include <cstdlib>
-
 int main(int argc, const char *argv[])
 try
 {