diff --git a/polymer-ui-icon/polymer-ui-icon.html b/polymer-ui-icon/polymer-ui-icon.html
index 87817be..0ca34fa 100644
--- a/polymer-ui-icon/polymer-ui-icon.html
+++ b/polymer-ui-icon/polymer-ui-icon.html
@@ -145,6 +145,7 @@
         updateIcon: function() {
           if (this.src) {
             this.style.backgroundPosition = 'center';
+            this.style.backgroundSize = this.size + 'px ' + this.size + 'px';
           } else {
             this.style.backgroundPosition = (this.bx + 'px') + ' ' + (this.by + 'px');
           }