diff --git a/chrome/content/zotero/xpcom/annotate.js b/chrome/content/zotero/xpcom/annotate.js
index e4dc78a5b..031b73f7d 100644
--- a/chrome/content/zotero/xpcom/annotate.js
+++ b/chrome/content/zotero/xpcom/annotate.js
@@ -652,7 +652,11 @@ Zotero.Annotation.prototype._addChildElements = function() {
 		
 		var img = this.document.createElement("img");
 		img.src = "chrome://zotero/skin/annotation-close.png";
-		img.addEventListener("click", function() { me._delete() }, false);
+		img.addEventListener("click", function(event) {
+			if (me._confirmDelete(event)) {
+				me._delete()
+			}
+		}, false);
 		div.appendChild(img);
 		
 		this.textarea = this.document.createElement("textarea");
@@ -676,6 +680,31 @@ Zotero.Annotation.prototype._click = function() {
 	this.div.style.zIndex = this.annotationsObj.zIndex;
 }
 
+Zotero.Annotation.prototype._confirmDelete = function(event) {
+	if (event.target.parentNode.nextSibling.value == '' ||
+		!Zotero.Prefs.get('annotations.warnOnClose')) {
+		return true;
+	}
+	
+	var promptService = Components.classes["@mozilla.org/embedcomp/prompt-service;1"]
+									.getService(Components.interfaces.nsIPromptService);
+	
+	var dontShowAgain = { value: false };
+	var del = promptService.confirmCheck(
+		this.window,
+		Zotero.getString('annotations.confirmClose.title'),
+		Zotero.getString('annotations.confirmClose.body'),
+		Zotero.getString('general.dontShowWarningAgain'),
+		dontShowAgain
+	);
+	
+	if (dontShowAgain.value) {
+		Zotero.Prefs.set('annotations.warnOnClose', false);
+	}
+	
+	return del;
+}
+
 Zotero.Annotation.prototype._delete = function() {
 	if(this.annotationID) {
 		Zotero.DB.query("DELETE FROM annotations WHERE annotationID = ?", [this.annotationID]);
diff --git a/chrome/locale/en-US/zotero/zotero.properties b/chrome/locale/en-US/zotero/zotero.properties
index ba7333e83..82a0fd0a8 100644
--- a/chrome/locale/en-US/zotero/zotero.properties
+++ b/chrome/locale/en-US/zotero/zotero.properties
@@ -1,3 +1,5 @@
+general.dontShowWarningAgain			= Don't show this warning again.
+
 pane.collections.delete			= Are you sure you want to delete the selected collection?
 pane.collections.deleteSearch	= Are you sure you want to delete the selected search?
 pane.collections.name			= Collection name:
@@ -293,4 +295,7 @@ date.abbreviation.day           = d
 citation.multipleSources		= Multiple Sources...
 citation.singleSource		= Single Source...
 
-report.title.default				= Zotero Report
\ No newline at end of file
+report.title.default				= Zotero Report
+
+annotations.confirmClose.title		= Are you sure you want to close this annotation?
+annotations.confirmClose.body		= All text will be lost.
\ No newline at end of file