diff --git a/externs/browser/html5.js b/externs/browser/html5.js
index cd7184cd930..ef9b9bc63f4 100644
--- a/externs/browser/html5.js
+++ b/externs/browser/html5.js
@@ -277,6 +277,16 @@ CanvasPathMethods.prototype.arcTo = function(x1, y1, x2, y2, radius) {};
  */
 CanvasPathMethods.prototype.rect = function(x, y, w, h) {};
 
+/**
+ * @param {number} x
+ * @param {number} y
+ * @param {number} w
+ * @param {number} h
+ * @param {(number|DOMPointInit|Array<number|DOMPointInit>)=} radii
+ * @return {undefined}
+ */
+CanvasPathMethods.prototype.roundRect = function(x, y, w, h, radii) {};
+
 /**
  * @param {number} x
  * @param {number} y
@@ -362,6 +372,17 @@ Path2D.prototype.arcTo = function(x1, y1, x2, y2, radius) {};
  */
 Path2D.prototype.rect = function(x, y, w, h) {};
 
+/**
+ * @param {number} x
+ * @param {number} y
+ * @param {number} w
+ * @param {number} h
+ * @param {(number|DOMPointInit|Array<number|DOMPointInit>)=} radii
+ * @return {undefined}
+ * @override
+ */
+Path2D.prototype.roundRect = function(x, y, w, h, radii) {};
+
 /**
  * @param {number} x
  * @param {number} y
@@ -660,6 +681,17 @@ BaseRenderingContext2D.prototype.arcTo = function(x1, y1, x2, y2, radius) {};
  */
 BaseRenderingContext2D.prototype.rect = function(x, y, w, h) {};
 
+/**
+ * @param {number} x
+ * @param {number} y
+ * @param {number} w
+ * @param {number} h
+ * @param {(number|DOMPointInit|Array<number|DOMPointInit>)=} radii
+ * @return {undefined}
+ * @override
+ */
+BaseRenderingContext2D.prototype.roundRect = function(x, y, w, h, radii) {};
+
 /**
  * @param {number} x
  * @param {number} y