diff --git a/library/src/com/manuelpeinado/fadingactionbar/FadingActionBarHelperBase.java b/library/src/com/manuelpeinado/fadingactionbar/FadingActionBarHelperBase.java
index 0721a66..128f35b 100644
--- a/library/src/com/manuelpeinado/fadingactionbar/FadingActionBarHelperBase.java
+++ b/library/src/com/manuelpeinado/fadingactionbar/FadingActionBarHelperBase.java
@@ -299,7 +299,17 @@ public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCoun
         public void onScrollStateChanged(AbsListView view, int scrollState) {
         }
     };
+    
     private int mLastScrollPosition;
+    private OnAlphaChangeListener mOnAlphaChangeListener;
+    
+    public static interface OnAlphaChangeListener {
+    	void onAlphaChanged(int alpha);
+    }
+    
+    public void setOnAlphaChangeListener(OnAlphaChangeListener l) {
+    	mOnAlphaChangeListener = l;
+    }
 
     private void onNewScroll(int scrollPosition) {
         if (isActionBarNull()) {
@@ -315,6 +325,9 @@ private void onNewScroll(int scrollPosition) {
         float ratio = (float) Math.min(Math.max(scrollPosition, 0), headerHeight) / headerHeight;
         int newAlpha = (int) (ratio * 255);
         mActionBarBackgroundDrawable.setAlpha(newAlpha);
+        if (mOnAlphaChangeListener != null) {
+        	mOnAlphaChangeListener.onAlphaChanged(newAlpha);
+        }
 
         addParallaxEffect(scrollPosition);
     }