diff --git a/util/sync_point.h b/util/sync_point.h
index a9aac755e..91fc30886 100644
--- a/util/sync_point.h
+++ b/util/sync_point.h
@@ -6,6 +6,7 @@
 
 #include <assert.h>
 #include <condition_variable>
+#include <functional>
 #include <mutex>
 #include <string>
 #include <unordered_set>