diff --git a/app/src/main/java/com/google/ar/core/examples/java/common/framework/RWT/RWTRenderer.java b/app/src/main/java/com/google/ar/core/examples/java/common/framework/RWT/RWTRenderer.java
index dbe10e2..965bd65 100644
--- a/app/src/main/java/com/google/ar/core/examples/java/common/framework/RWT/RWTRenderer.java
+++ b/app/src/main/java/com/google/ar/core/examples/java/common/framework/RWT/RWTRenderer.java
@@ -1,5 +1,6 @@
 package com.google.ar.core.examples.java.common.framework.RWT;
 
+import android.opengl.GLES20;
 import android.opengl.GLSurfaceView.Renderer;
 
 import com.google.ar.core.Camera;
@@ -63,7 +64,7 @@
 
 	@Override
 	public void onSurfaceChanged(GL10 gl, int width, int height) {
-		gl.glViewport(0, 0, width, height);
+		GLES20.glViewport(0, 0, width, height);
 
 		if (viewer == null) {
 			gc3D = new GraphicsContext3D(gl);