diff --git a/src/policy_cache.hpp b/src/policy_cache.hpp
index ce2045d7..5c46c8bf 100644
--- a/src/policy_cache.hpp
+++ b/src/policy_cache.hpp
@@ -19,8 +19,7 @@
 #pragma once
 
 #include "nonstd/optional.hpp"
-
-#include <boost/unordered/concurrent_flat_map.hpp>
+#include "boost/unordered/concurrent_flat_map.hpp"
 
 #include <cstdint>
 #include <string>