diff --git a/html5/js/Client.js b/html5/js/Client.js
index 1e40328d..5d9a323c 100644
--- a/html5/js/Client.js
+++ b/html5/js/Client.js
@@ -3032,7 +3032,7 @@ XpraClient.prototype._process_notify_show = function(packet, ctx) {
 	function notify() {
 		let icon_url = "";
 		if (icon && icon[0]=="png") {
-			icon_url = "data:image/png;base64," + Utilities.ArrayBufferToBase64(icon[3]);
+			icon_url = "data:image/png;base64," + Utilities.ToBase64(icon[3]);
 			console.log("notification icon_url=", icon_url);
 		}
 		/*
diff --git a/html5/js/Utilities.js b/html5/js/Utilities.js
index 66e66625..f2d46538 100644
--- a/html5/js/Utilities.js
+++ b/html5/js/Utilities.js
@@ -460,6 +460,15 @@ const Utilities = {
 		return window.btoa(s);
 	},
 
+	ToBase64 : function(v) {
+		try {
+			return window.btoa(v);
+		}
+		catch (e) {
+			return ArrayBufferToBase64(v);
+		}
+	},
+
 	convertDataURIToBinary : function (dataURI) {
 		const BASE64_MARKER = ';base64,';
 		const base64Index = dataURI.indexOf(BASE64_MARKER) + BASE64_MARKER.length;