--- UbiNodeCensus.h
+++ UbiNodeCensus.h
@@ -4,16 +4,18 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef js_UbiNodeCensus_h
 #define js_UbiNodeCensus_h
 
 #include "mozilla/Move.h"
 
+#include "jsapi.h"
+
 #include "js/UbiNode.h"
 #include "js/UbiNodeTraverse.h"
 
 // A census is a ubi::Node traversal that assigns each node to one or more
 // buckets, and returns a report with the size of each bucket.
 //
 // We summarize the results of a census with counts broken down according to
 // criteria selected by the API consumer code that is requesting the census. For