diff --git a/examples/feature-animation.js b/examples/feature-animation.js
index 00d97d98fc..8295ec745d 100644
--- a/examples/feature-animation.js
+++ b/examples/feature-animation.js
@@ -72,8 +72,7 @@ function flash(feature) {
       snapToPixel: false,
       stroke: new ol.style.Stroke({
         color: 'rgba(255, 0, 0, ' + opacity + ')',
-        width: 1,
-        opacity: opacity
+        width: 1
       })
     });
 
diff --git a/src/ol/style/circlestyle.js b/src/ol/style/circlestyle.js
index 57bb47061a..e9d7a2e9ab 100644
--- a/src/ol/style/circlestyle.js
+++ b/src/ol/style/circlestyle.js
@@ -405,7 +405,7 @@ ol.style.Circle.prototype.drawHitDetectionCanvas_ =
       renderOptions.size / 2, renderOptions.size / 2,
       this.radius_, 0, 2 * Math.PI, true);
 
-  context.fillStyle = ol.render.canvas.defaultFillStyle;
+  context.fillStyle = ol.color.asString(ol.render.canvas.defaultFillStyle);
   context.fill();
   if (!goog.isNull(this.stroke_)) {
     context.strokeStyle = renderOptions.strokeStyle;