diff --git a/src/ray/object_manager/common.h b/src/ray/object_manager/common.h
index d48f72c96..989113995 100644
--- a/src/ray/object_manager/common.h
+++ b/src/ray/object_manager/common.h
@@ -1,6 +1,8 @@
 
 #pragma once
 
+#include <functional>
+
 namespace ray {
 
 /// A callback to asynchronously spill objects when space is needed. The