diff --git a/chrome/content/zotero/xpcom/reader.js b/chrome/content/zotero/xpcom/reader.js
index 4f8c07acb2..f330fd9772 100644
--- a/chrome/content/zotero/xpcom/reader.js
+++ b/chrome/content/zotero/xpcom/reader.js
@@ -193,6 +193,7 @@ class ReaderInstance {
 		catch {
 			// Reader was closed before it could be initialized
 			// No need to log this
+			this._blockingObserver = null;
 		}
 
 		// Prepare Fluent data