diff --git a/chrome/content/zotero/xpcom/reader.js b/chrome/content/zotero/xpcom/reader.js
index 7c241a7ae0..e0f7bcc254 100644
--- a/chrome/content/zotero/xpcom/reader.js
+++ b/chrome/content/zotero/xpcom/reader.js
@@ -830,7 +830,18 @@ class ReaderTab extends ReaderInstance {
 				});
 
 				this._iframeWindow.wrappedJSObject.zoteroConfirmDeletion = function (plural) {
-					return Services.prompt.confirm(null, '', Zotero.getString('pdfReader.deleteAnnotation.' + (plural ? 'plural' : 'singular')));
+					let ps = Services.prompt;
+					let buttonFlags = ps.BUTTON_POS_0 * ps.BUTTON_TITLE_IS_STRING
+						+ ps.BUTTON_POS_1 * ps.BUTTON_TITLE_CANCEL;
+					let index = ps.confirmEx(
+						null,
+						'',
+						Zotero.getString('pdfReader.deleteAnnotation.' + (plural ? 'plural' : 'singular')),
+						buttonFlags,
+						Zotero.getString('general.delete'),
+						null, null, null, {}
+					);
+					return !index;
 				};
 			}
 		});
diff --git a/chrome/locale/en-US/zotero/zotero.properties b/chrome/locale/en-US/zotero/zotero.properties
index 20263a26a5..a07ba0a6f9 100644
--- a/chrome/locale/en-US/zotero/zotero.properties
+++ b/chrome/locale/en-US/zotero/zotero.properties
@@ -1375,8 +1375,8 @@ pdfReader.thisPage = This page
 pdfReader.thisPageAndLaterPages = This page and later pages
 pdfReader.allPages = All pages
 pdfReader.autoDetect = Auto-Detect
-pdfReader.deleteAnnotation.singular = Delete the selected annotation?
-pdfReader.deleteAnnotation.plural = Delete selected annotations?
+pdfReader.deleteAnnotation.singular = Are you sure you want to delete the selected annotation?
+pdfReader.deleteAnnotation.plural = Are you sure you want to delete the selected annotations?
 
 spellCheck.checkSpelling = Check Spelling
 spellCheck.addRemoveDictionaries = Add/Remove Dictionaries…