diff --git a/chrome/content/zotero/xpcom/attachments.js b/chrome/content/zotero/xpcom/attachments.js
index 113e2de61..32e641012 100644
--- a/chrome/content/zotero/xpcom/attachments.js
+++ b/chrome/content/zotero/xpcom/attachments.js
@@ -1487,6 +1487,7 @@ Zotero.Attachments = new function(){
 	 */
 	this.isPDFJS = function(doc) {
 		// pdf.js HACK
+		// This may no longer be necessary (as of Fx 23)
 		if(doc.contentType === "text/html") {
 			var win = doc.defaultView;
 			if(win) {
diff --git a/chrome/content/zotero/zoteroPane.js b/chrome/content/zotero/zoteroPane.js
index 13591ae6c..d8268d8fc 100644
--- a/chrome/content/zotero/zoteroPane.js
+++ b/chrome/content/zotero/zoteroPane.js
@@ -3087,7 +3087,8 @@ var ZoteroPane = new function()
 		if (itemType == 'temporaryPDFHack') {
 			itemType = null;
 			var isPDF = false;
-			if (doc.title.indexOf('application/pdf') != -1 || Zotero.Attachments.isPDFJS(doc)) {
+			if (doc.title.indexOf('application/pdf') != -1 || Zotero.Attachments.isPDFJS(doc)
+					|| doc.contentType == 'application/pdf') {
 				isPDF = true;
 			}
 			else {