diff --git a/docs/component/canvas.md b/docs/component/canvas.md
index 39d9b9d1749537ae4319d4a57e4ad65b1738eccc..f712448f5b87bf339a73be29902b64fc88cc5f73 100644
--- a/docs/component/canvas.md
+++ b/docs/component/canvas.md
@@ -45,7 +45,7 @@
 <script>
 export default {
 	onReady: function (e) {
-		var context = uni.createCanvasContext('firstCanvas')
+		var context = uni.createCanvasContext('firstCanvas', this)
 		context.setStrokeStyle("#00ff00")
 		context.setLineWidth(5)
 		context.rect(0, 0, 200, 200)