diff --git a/chrome/content/zotero/itemTree.jsx b/chrome/content/zotero/itemTree.jsx
index c2526a0f69..8969ea621c 100644
--- a/chrome/content/zotero/itemTree.jsx
+++ b/chrome/content/zotero/itemTree.jsx
@@ -2189,8 +2189,11 @@ var ItemTree = class ItemTree extends LibraryTree {
 					}
 
 					// Don't allow web attachments to be dragged out of parents,
-					// but do allow PDFs for now so they can be recognized
-					if (item.isWebAttachment() && item.attachmentContentType != 'application/pdf') {
+					// except for files that can be recognized
+					if (item.isWebAttachment()
+							// Keep in sync with Zotero.RecognizeDocument.canRecognize()
+							&& !item.isPDFAttachment()
+							&& !item.isEPUBAttachment()) {
 						return false;
 					}
 
diff --git a/chrome/content/zotero/xpcom/recognizeDocument.js b/chrome/content/zotero/xpcom/recognizeDocument.js
index 43052592e8..4e590fb83c 100644
--- a/chrome/content/zotero/xpcom/recognizeDocument.js
+++ b/chrome/content/zotero/xpcom/recognizeDocument.js
@@ -131,6 +131,7 @@ Zotero.RecognizeDocument = new function () {
 	 */
 	this.canRecognize = function (item) {
 		return item.attachmentContentType
+			// Keep in sync with dragging out of parent in ItemTree::canDropCheck()
 			&& (item.isPDFAttachment() || item.isEPUBAttachment())
 			&& item.isTopLevelItem();
 	};