diff --git a/chrome/content/zotero/xpcom/reader.js b/chrome/content/zotero/xpcom/reader.js
index 2ad2aaf620..b388c2d621 100644
--- a/chrome/content/zotero/xpcom/reader.js
+++ b/chrome/content/zotero/xpcom/reader.js
@@ -531,7 +531,10 @@ class ReaderInstance {
 		if (fileSize > ARRAYBUFFER_MAX_LENGTH) {
 			throw new Error(`The file "${path}" is too large`);
 		}
-		let buf = await OS.File.read(path, {});
+		let buf;
+		if (this._type !== 'pdf') {
+			buf = await OS.File.read(path, {});
+		}
 		let baseURI = `zotero://attachment/${Zotero.API.getLibraryPrefix(item.libraryID)}/items/${item.key}/`;
 		return {
 			buf,
diff --git a/reader b/reader
index 005a88eb6c..81863a19d7 160000
--- a/reader
+++ b/reader
@@ -1 +1 @@
-Subproject commit 005a88eb6cfcfdc808395f3e865040fe33715183
+Subproject commit 81863a19d7f62685e6c3ab8ce893647b9dfb7351