diff --git a/chrome/locale/en-US/zotero/reader.ftl b/chrome/locale/en-US/zotero/reader.ftl
index ac6300b392..f5afe96065 100644
--- a/chrome/locale/en-US/zotero/reader.ftl
+++ b/chrome/locale/en-US/zotero/reader.ftl
@@ -128,6 +128,7 @@ reader-foreground = Foreground:
 reader-reading-mode = Reading Mode
 reader-reading-mode-not-supported = Reading Mode is not supported in this document.
 reader-clear-selection = Clear Selection
+reader-epub-encrypted = This ebook is encrypted and cannot be opened.
 
 reader-move-annotation-start-key =
     { PLATFORM() ->