diff --git a/recyclerviewfastscroller/src/main/java/xyz/danoz/recyclerviewfastscroller/AbsRecyclerViewFastScroller.java b/recyclerviewfastscroller/src/main/java/xyz/danoz/recyclerviewfastscroller/AbsRecyclerViewFastScroller.java
index 5b88dfc..5988a83 100644
--- a/recyclerviewfastscroller/src/main/java/xyz/danoz/recyclerviewfastscroller/AbsRecyclerViewFastScroller.java
+++ b/recyclerviewfastscroller/src/main/java/xyz/danoz/recyclerviewfastscroller/AbsRecyclerViewFastScroller.java
@@ -198,9 +198,7 @@ public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
     protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
         super.onLayout(changed, left, top, right, bottom);
 
-        if (getScrollProgressCalculator() == null) {
-            onCreateScrollProgressCalculator();
-        }
+        onCreateScrollProgressCalculator();
 
         // synchronize the handle position to the RecyclerView
         float scrollProgress = getScrollProgressCalculator().calculateScrollProgress(mRecyclerView);
diff --git a/recyclerviewfastscroller/src/main/java/xyz/danoz/recyclerviewfastscroller/calculation/VerticalScrollBoundsProvider.java b/recyclerviewfastscroller/src/main/java/xyz/danoz/recyclerviewfastscroller/calculation/VerticalScrollBoundsProvider.java
index cffb665..12edd37 100644
--- a/recyclerviewfastscroller/src/main/java/xyz/danoz/recyclerviewfastscroller/calculation/VerticalScrollBoundsProvider.java
+++ b/recyclerviewfastscroller/src/main/java/xyz/danoz/recyclerviewfastscroller/calculation/VerticalScrollBoundsProvider.java
@@ -5,8 +5,8 @@
  */
 public class VerticalScrollBoundsProvider {
 
-    private final float mMinimumScrollY;
-    private final float mMaximumScrollY;
+    private float mMinimumScrollY;
+    private float mMaximumScrollY;
 
     public VerticalScrollBoundsProvider(float minimumScrollY, float maximumScrollY) {
         mMinimumScrollY = minimumScrollY;
@@ -20,4 +20,9 @@ public float getMinimumScrollY() {
     public float getMaximumScrollY() {
         return mMaximumScrollY;
     }
+
+    public void update(float minimumScrollY, float maximumScrollY) {
+        mMinimumScrollY = minimumScrollY;
+        mMaximumScrollY = maximumScrollY;
+    }
 }
diff --git a/recyclerviewfastscroller/src/main/java/xyz/danoz/recyclerviewfastscroller/vertical/VerticalRecyclerViewFastScroller.java b/recyclerviewfastscroller/src/main/java/xyz/danoz/recyclerviewfastscroller/vertical/VerticalRecyclerViewFastScroller.java
index 511ac08..6f02f08 100644
--- a/recyclerviewfastscroller/src/main/java/xyz/danoz/recyclerviewfastscroller/vertical/VerticalRecyclerViewFastScroller.java
+++ b/recyclerviewfastscroller/src/main/java/xyz/danoz/recyclerviewfastscroller/vertical/VerticalRecyclerViewFastScroller.java
@@ -1,6 +1,7 @@
 package xyz.danoz.recyclerviewfastscroller.vertical;
 
 import android.content.Context;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
@@ -21,8 +22,9 @@
  */
 public class VerticalRecyclerViewFastScroller extends AbsRecyclerViewFastScroller implements RecyclerViewScroller {
 
-    @Nullable private VerticalScrollProgressCalculator mScrollProgressCalculator;
-    @Nullable private VerticalScreenPositionCalculator mScreenPositionCalculator;
+    private VerticalScrollProgressCalculator mScrollProgressCalculator;
+    private VerticalScreenPositionCalculator mScreenPositionCalculator;
+    private VerticalScrollBoundsProvider boundsProvider;
 
     public VerticalRecyclerViewFastScroller(Context context) {
         this(context, null);
@@ -34,6 +36,13 @@ public VerticalRecyclerViewFastScroller(Context context, AttributeSet attrs) {
 
     public VerticalRecyclerViewFastScroller(Context context, AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
+        init();
+    }
+
+    private void init() {
+        boundsProvider = new VerticalScrollBoundsProvider(mBar.getY(), mBar.getY() + mBar.getHeight() - mHandle.getHeight());
+        mScrollProgressCalculator = new VerticalLinearLayoutManagerScrollProgressCalculator(boundsProvider);
+        mScreenPositionCalculator = new VerticalScreenPositionCalculator(boundsProvider);
     }
 
     @Override
@@ -55,10 +64,8 @@ public void moveHandleToPosition(float scrollProgress) {
         mHandle.setY(mScreenPositionCalculator.getYPositionFromScrollProgress(scrollProgress));
     }
 
+    @Override
     protected void onCreateScrollProgressCalculator() {
-        VerticalScrollBoundsProvider boundsProvider =
-                new VerticalScrollBoundsProvider(mBar.getY(), mBar.getY() + mBar.getHeight() - mHandle.getHeight());
-        mScrollProgressCalculator = new VerticalLinearLayoutManagerScrollProgressCalculator(boundsProvider);
-        mScreenPositionCalculator = new VerticalScreenPositionCalculator(boundsProvider);
+        boundsProvider.update(mBar.getY(), mBar.getY() + mBar.getHeight() - mHandle.getHeight());
     }
 }