diff --git a/mfbt/AllocPolicy.h b/mfbt/AllocPolicy.h
index b8d9b4f054c0..4a8c84bf460b 100644
--- a/mfbt/AllocPolicy.h
+++ b/mfbt/AllocPolicy.h
@@ -12,6 +12,7 @@
 #ifndef mozilla_AllocPolicy_h
 #define mozilla_AllocPolicy_h
 
+#include "mozilla/NullPtr.h"
 #include "mozilla/TemplateLib.h"
 
 #include <stddef.h>