diff --git a/src/core/core.helpers.js b/src/core/core.helpers.js
index 60673d8fa..632883f8d 100644
--- a/src/core/core.helpers.js
+++ b/src/core/core.helpers.js
@@ -944,6 +944,7 @@ module.exports = function(Chart) {
 		}
 	};
 	helpers.getHoverColor = function(color) {
+		/* global CanvasGradient */
 		return (color instanceof CanvasPattern) ?
 			color :
 			helpers.color(color).saturate(0.5).darken(0.1).rgbString();