diff --git a/dom/bindings/CallbackObject.h b/dom/bindings/CallbackObject.h
index 71e92472d7bf..c8517544d70d 100644
--- a/dom/bindings/CallbackObject.h
+++ b/dom/bindings/CallbackObject.h
@@ -25,6 +25,7 @@
 #include "mozilla/ErrorResult.h"
 #include "mozilla/HoldDropJSObjects.h"
 #include "mozilla/MemoryReporting.h"
+#include "mozilla/OwningNonNull.h"
 #include "mozilla/dom/ScriptSettings.h"
 #include "nsWrapperCache.h"
 #include "nsJSEnvironment.h"