diff --git a/docs/api/en/renderers/WebGLRenderer.html b/docs/api/en/renderers/WebGLRenderer.html
index 492c61749772bdfc3c172fc674e876e46510e5f7..33248593d01ce95b015a622d53a2d8bad2ed6024 100644
--- a/docs/api/en/renderers/WebGLRenderer.html
+++ b/docs/api/en/renderers/WebGLRenderer.html
@@ -348,8 +348,12 @@
 		<h3>[method:RenderTarget getRenderTarget]()</h3>
 		<p>Returns the current RenderTarget, if any.</p>
 
-		<h3>[method:RenderTarget getCurrentViewport]()</h3>
-		<p>Returns the current viewport.</p>
+		<h3>[method:Vector4 getCurrentViewport]( [param:Vector4 target] )</h3>
+		<p>
+		[page:Vector4 target] — the result will be copied into this Vector4.<br /><br />
+
+		Returns the current viewport.
+		</p>
 
 		<h3>[method:Object getDrawingBufferSize]()</h3>
 		<p>Returns an object containing the width and height of the renderer's drawing buffer, in pixels.</p>
diff --git a/examples/js/objects/Lensflare.js b/examples/js/objects/Lensflare.js
index 67cdd0eeb0bcc9dc5c2caa1d8ac57d115ccdae8b..57a92cd36779ce7d79062c432dc10c0af5a05d7e 100644
--- a/examples/js/objects/Lensflare.js
+++ b/examples/js/objects/Lensflare.js
@@ -162,7 +162,7 @@ THREE.Lensflare = function () {
 
 	this.onBeforeRender = function ( renderer, scene, camera ) {
 
-		viewport.copy( renderer.getCurrentViewport() );
+		renderer.getCurrentViewport( viewport );
 
 		var invAspect = viewport.w / viewport.z;
 		var halfViewportWidth = viewport.z / 2.0;
diff --git a/src/renderers/WebGLRenderer.d.ts b/src/renderers/WebGLRenderer.d.ts
index 2e70c1e27cb62528d25c1074c23b7f771ed524a9..02c92f70f22000fc350f028b9582d767299970f4 100644
--- a/src/renderers/WebGLRenderer.d.ts
+++ b/src/renderers/WebGLRenderer.d.ts
@@ -213,7 +213,7 @@ export class WebGLRenderer implements Renderer {
    */
   setSize(width: number, height: number, updateStyle?: boolean): void;
 
-  getCurrentViewport(): Vector4;
+  getCurrentViewport(target: Vector4): Vector4;
   /**
    * Sets the viewport to render from (x, y) to (x + width, y + height).
    */
diff --git a/src/renderers/WebGLRenderer.js b/src/renderers/WebGLRenderer.js
index 68e20dd4f89169d867099637511ed01d8173d905..5fb201672c123fb4eccf69ae983a09b94bd868a9 100644
--- a/src/renderers/WebGLRenderer.js
+++ b/src/renderers/WebGLRenderer.js
@@ -418,9 +418,17 @@ function WebGLRenderer( parameters ) {
 
 	};
 
-	this.getCurrentViewport = function () {
+	this.getCurrentViewport = function ( target ) {
 
-		return _currentViewport;
+		if ( target === undefined ) {
+
+			console.warn( 'WebGLRenderer: .getCurrentViewport() now requires a Vector4 as an argument' );
+
+			target = new Vector4();
+
+		}
+
+		return target.copy( _currentViewport );
 
 	};