diff --git a/library/res/values/attrs.xml b/library/res/values/attrs.xml
index e786569..52868c3 100644
--- a/library/res/values/attrs.xml
+++ b/library/res/values/attrs.xml
@@ -9,6 +9,10 @@
         <attr name="progress_background_color" format="color" />
         <attr name="thumb_visible" format="boolean" />
         <attr name="marker_visible" format="boolean" />
+        <attr name="thumb_shape" format="enum">
+            <enum name="square" value="0" />
+            <enum name="circle" value="1" />
+        </attr>
         <attr name="android:gravity" />
     </declare-styleable>
 
diff --git a/library/res/values/styles.xml b/library/res/values/styles.xml
index 24f2c2d..3722d83 100644
--- a/library/res/values/styles.xml
+++ b/library/res/values/styles.xml
@@ -9,6 +9,7 @@
         <item name="progress_background_color">#ffffffff</item>
         <item name="marker_visible">true</item>
         <item name="thumb_visible">true</item>
+        <item name="thumb_shape">square</item>
     </style>
     
     <style name="CircularProgressBarLight">
@@ -20,5 +21,6 @@
         <item name="progress_background_color">#aaa</item>
         <item name="marker_visible">true</item>
         <item name="thumb_visible">true</item>
+        <item name="thumb_shape">square</item>
     </style>
 </resources>
\ No newline at end of file
diff --git a/library/src/com/pascalwelsch/holocircularprogressbar/HoloCircularProgressBar.java b/library/src/com/pascalwelsch/holocircularprogressbar/HoloCircularProgressBar.java
index 0961b57..8abb30b 100644
--- a/library/src/com/pascalwelsch/holocircularprogressbar/HoloCircularProgressBar.java
+++ b/library/src/com/pascalwelsch/holocircularprogressbar/HoloCircularProgressBar.java
@@ -26,6 +26,13 @@
  */
 public class HoloCircularProgressBar extends View {
 
+    /**
+     * Types of thumb shape
+     */
+    public enum ThumbShape {
+        Square, Circle
+    }
+
     /**
      * TAG constant for logging
      */
@@ -67,13 +74,18 @@ public class HoloCircularProgressBar extends View {
      */
     private static final String INSTANCE_STATE_MARKER_VISIBLE = "marker_visible";
 
+    /**
+     * used to save and restore the type of the thumb in this instance
+     */
+    private static final String INSTANCE_STATE_THUMB_TYPE = "thumb_type";
+
     /**
      * The rectangle enclosing the circle.
      */
     private final RectF mCircleBounds = new RectF();
 
     /**
-     * the rect for the thumb square
+     * the rect for the thumb shape
      */
     private final RectF mSquareRect = new RectF();
 
@@ -184,6 +196,11 @@ public class HoloCircularProgressBar extends View {
      */
     private int mThumbRadius = 20;
 
+    /**
+     * The type of Thumb shape to draw.
+     */
+    private ThumbShape mThumbShape = ThumbShape.Square;
+
     /**
      * The Translation offset x which gives us the ability to use our own coordinates system.
      */
@@ -252,6 +269,9 @@ public HoloCircularProgressBar(final Context context, final AttributeSet attrs,
                         .getBoolean(R.styleable.HoloCircularProgressBar_thumb_visible, true));
                 setMarkerEnabled(attributes
                         .getBoolean(R.styleable.HoloCircularProgressBar_marker_visible, true));
+                setThumbShape(ThumbShape.values()[
+                        attributes.getInt(R.styleable.HoloCircularProgressBar_thumb_shape, 0)
+                        ]);
 
                 mGravity = attributes
                         .getInt(R.styleable.HoloCircularProgressBar_android_gravity,
@@ -310,13 +330,21 @@ protected void onDraw(final Canvas canvas) {
             // draw the thumb square at the correct rotated position
             canvas.save();
             canvas.rotate(progressRotation - 90);
-            // rotate the square by 45 degrees
-            canvas.rotate(45, mThumbPosX, mThumbPosY);
-            mSquareRect.left = mThumbPosX - mThumbRadius / 3;
-            mSquareRect.right = mThumbPosX + mThumbRadius / 3;
-            mSquareRect.top = mThumbPosY - mThumbRadius / 3;
-            mSquareRect.bottom = mThumbPosY + mThumbRadius / 3;
-            canvas.drawRect(mSquareRect, mThumbColorPaint);
+
+
+            if (mThumbShape == ThumbShape.Square) {
+                // rotate the square by 45 degrees
+                canvas.rotate(45, mThumbPosX, mThumbPosY);
+                mSquareRect.left = mThumbPosX - mThumbRadius / 3;
+                mSquareRect.right = mThumbPosX + mThumbRadius / 3;
+                mSquareRect.top = mThumbPosY - mThumbRadius / 3;
+                mSquareRect.bottom = mThumbPosY + mThumbRadius / 3;
+                canvas.drawRect(mSquareRect, mThumbColorPaint);
+            } else {
+                canvas.drawCircle(mThumbPosX, mThumbPosY,
+                        mThumbRadius/2, mThumbColorPaint);
+            }
+
             canvas.restore();
         }
     }
@@ -396,6 +424,11 @@ protected void onRestoreInstanceState(final Parcelable state) {
 
             mIsMarkerEnabled = bundle.getBoolean(INSTANCE_STATE_MARKER_VISIBLE);
 
+            final ThumbShape thumbShape = ThumbShape.values()[bundle.getInt(INSTANCE_STATE_THUMB_TYPE)];
+            if (thumbShape != mThumbShape) {
+                setThumbShape(thumbShape);
+            }
+
             super.onRestoreInstanceState(bundle.getParcelable(INSTANCE_STATE_SAVEDSTATE));
             return;
         }
@@ -413,6 +446,7 @@ protected Parcelable onSaveInstanceState() {
         bundle.putInt(INSTANCE_STATE_PROGRESS_BACKGROUND_COLOR, mProgressBackgroundColor);
         bundle.putBoolean(INSTANCE_STATE_THUMB_VISIBLE, mIsThumbEnabled);
         bundle.putBoolean(INSTANCE_STATE_MARKER_VISIBLE, mIsMarkerEnabled);
+        bundle.putInt(INSTANCE_STATE_THUMB_TYPE, mThumbShape.ordinal());
         return bundle;
     }
 
@@ -460,6 +494,15 @@ public boolean isThumbEnabled() {
         return mIsThumbEnabled;
     }
 
+    /**
+     * Gets the thumb shape.
+     *
+     * @return the shape of the thumb
+     */
+    public ThumbShape getThumbShape() {
+        return mThumbShape;
+    }
+
     /**
      * Sets the marker enabled.
      *
@@ -540,6 +583,17 @@ public void setThumbEnabled(final boolean enabled) {
         mIsThumbEnabled = enabled;
     }
 
+    /**
+     * sets the shape of the thumb
+     *
+     * @param shape shape of the thumb
+     */
+    public void setThumbShape(ThumbShape shape) {
+        mThumbShape = shape;
+        if (mIsThumbEnabled)
+            invalidate();
+    }
+
     /**
      * Sets the wheel size.
      *
@@ -657,8 +711,6 @@ private void updateProgressColor() {
         mThumbColorPaint.setColor(mProgressColor);
         mThumbColorPaint.setStyle(Paint.Style.FILL_AND_STROKE);
         mThumbColorPaint.setStrokeWidth(mCircleStrokeWidth);
-
         invalidate();
     }
-
 }