diff --git a/assets/shaders/vertex.glsl b/assets/shaders/vertex.glsl
index d61ce54..42ea59e 100644
--- a/assets/shaders/vertex.glsl
+++ b/assets/shaders/vertex.glsl
@@ -1,11 +1,12 @@
 
 uniform mat4 projection;
+uniform mat4 modelview;
 attribute vec3 pos;
 attribute vec3 color;
 varying vec3 color_i;
 
 void main()
 {
-    gl_Position = projection * vec4(pos * 0.75, 1);
+    gl_Position = projection * modelview * vec4(pos * 0.75, 1);
     color_i = color;
 }
diff --git a/src/com/homelinux/holtrop/opengltest/MyGLSurfaceView.java b/src/com/homelinux/holtrop/opengltest/MyGLSurfaceView.java
index 9821f24..92c4e39 100644
--- a/src/com/homelinux/holtrop/opengltest/MyGLSurfaceView.java
+++ b/src/com/homelinux/holtrop/opengltest/MyGLSurfaceView.java
@@ -13,7 +13,5 @@ public class MyGLSurfaceView extends GLSurfaceView
         setEGLContextClientVersion(2);
 
         setRenderer(new MyRenderer(am));
-
-        setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
     }
 }
diff --git a/src/com/homelinux/holtrop/opengltest/MyRenderer.java b/src/com/homelinux/holtrop/opengltest/MyRenderer.java
index b8ae47f..c3bbf19 100644
--- a/src/com/homelinux/holtrop/opengltest/MyRenderer.java
+++ b/src/com/homelinux/holtrop/opengltest/MyRenderer.java
@@ -15,6 +15,7 @@ import java.io.InputStreamReader;
 import java.io.BufferedReader;
 import java.io.IOException;
 import android.opengl.Matrix;
+import android.os.SystemClock;
 
 public class MyRenderer implements GLSurfaceView.Renderer
 {
@@ -23,6 +24,7 @@ public class MyRenderer implements GLSurfaceView.Renderer
     private FloatBuffer m_quad_attrib_buffer;
     private AssetManager m_asset_manager;
     private float m_proj_matrix[] = new float[16];
+    private float m_modelview[] = new float[16];
 
     public MyRenderer(AssetManager am)
     {
@@ -115,7 +117,12 @@ public class MyRenderer implements GLSurfaceView.Renderer
     {
         GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
 
-        checkGLError("glBindBuffer");
+        long time = SystemClock.uptimeMillis() % 4000L;
+        float angle = 0.090f * ((int) time);
+        Matrix.setRotateM(m_modelview, 0, angle, 0, 0, 1);
+        GLES20.glUniformMatrix4fv(
+                GLES20.glGetUniformLocation(m_program, "modelview"),
+                1, false, m_modelview, 0);
         int attr_pos = GLES20.glGetAttribLocation(m_program, "pos");
         int attr_color = GLES20.glGetAttribLocation(m_program, "color");
         GLES20.glEnableVertexAttribArray(attr_pos);