diff --git a/chrome/content/zotero/xpcom/attachments.js b/chrome/content/zotero/xpcom/attachments.js
index a30bd0f3a0..1f84c1a39f 100644
--- a/chrome/content/zotero/xpcom/attachments.js
+++ b/chrome/content/zotero/xpcom/attachments.js
@@ -299,6 +299,7 @@ Zotero.Attachments = new function(){
 								Zotero.MIME.sniffForMIMEType(str) != 'application/pdf') {
 							Zotero.debug("Downloaded PDF did not have MIME type "
 								+ "'application/pdf' in Attachments.importFromURL()", 2);
+							Zotero.debug(str);
 							attachmentItem.erase();
 							return;
 						}