diff --git a/lib/lib.dom.d.ts b/lib/lib.dom.d.ts
index 94fb13c32ed0b..bd3c0e0977a31 100644
--- a/lib/lib.dom.d.ts
+++ b/lib/lib.dom.d.ts
@@ -4339,9 +4339,9 @@ interface HTMLCanvasElement extends HTMLElement {
       * Returns an object that provides methods and properties for drawing and manipulating images and graphics on a canvas element in a document. A context object includes information about colors, line widths, fonts, and other graphic parameters that can be drawn on a canvas.
       * @param contextId The identifier (ID) of the type of canvas to create. Internet Explorer 9 and Internet Explorer 10 support only a 2-D context using canvas.getContext("2d"); IE11 Preview also supports 3-D or WebGL context using canvas.getContext("experimental-webgl");
       */
-    getContext(contextId: "2d", contextAttributes?: Canvas2DContextAttributes): CanvasRenderingContext2D | null;
-    getContext(contextId: "webgl" | "experimental-webgl", contextAttributes?: WebGLContextAttributes): WebGLRenderingContext | null;
-    getContext(contextId: string, contextAttributes?: {}): CanvasRenderingContext2D | WebGLRenderingContext | null;
+    getContext(contextId: "2d", contextAttributes?: Canvas2DContextAttributes): CanvasRenderingContext2D;
+    getContext(contextId: "webgl" | "experimental-webgl", contextAttributes?: WebGLContextAttributes): WebGLRenderingContext;
+    getContext(contextId: string, contextAttributes?: {}): null;
     /**
       * Returns a blob object encoded as a Portable Network Graphics (PNG) format from a canvas image or drawing.
       */