diff --git a/chrome/content/zotero/xpcom/csl.js b/chrome/content/zotero/xpcom/csl.js
index df40c9e15e..b0ed915c06 100644
--- a/chrome/content/zotero/xpcom/csl.js
+++ b/chrome/content/zotero/xpcom/csl.js
@@ -1776,6 +1776,7 @@ Zotero.CSL.Item._zoteroFieldMap = {
 		"volume":"volume",
 		"issue":"issue",
 		"number-of-volumes":"numberOfVolumes",
+		"number-of-pages":"numPages",
 		"edition":"edition",
 		"version":"version",
 		"section":"section",