diff --git a/src/pixi/primitives/Graphics.js b/src/pixi/primitives/Graphics.js
index 7a80553..cd599fa 100644
--- a/src/pixi/primitives/Graphics.js
+++ b/src/pixi/primitives/Graphics.js
@@ -132,7 +132,7 @@
 {
 	this.filling = true;
 	this.fillColor = color || 0;
-	this.fillAlpha = alpha || 1;
+	this.fillAlpha = (alpha == undefined) ? 1 : alpha;
 }
 
 /**