diff --git a/chrome/content/zotero/recognizePDF.js b/chrome/content/zotero/recognizePDF.js
index 102328dc0c..5fc95aa3b0 100644
--- a/chrome/content/zotero/recognizePDF.js
+++ b/chrome/content/zotero/recognizePDF.js
@@ -39,8 +39,8 @@ var Zotero_RecognizePDF = new function() {
 	 * @returns {Boolean} True if the PDF can be recognized, false if it cannot be
 	 */
 	this.canRecognize = function(/**Zotero.Item*/ item) {
-		return item.attachmentMIMEType
-			&& item.attachmentMIMEType == "application/pdf"
+		return item.attachmentContentType
+			&& item.attachmentContentType == "application/pdf"
 			&& item.isTopLevelItem();
 	}