diff --git a/src/perfect-scrollbar.js b/src/perfect-scrollbar.js
index cc882dd..64aed6a 100644
--- a/src/perfect-scrollbar.js
+++ b/src/perfect-scrollbar.js
@@ -277,10 +277,16 @@
 
       // bind handlers
       var bindMouseWheelHandler = function () {
+        // FIXME: Backward compatibility.
+        // After e.deltaFactor applied, wheelSpeed should have smaller value.
+        // Currently, there's no way to change the settings after the scrollbar initialized.
+        // But if the way is implemented in the future, wheelSpeed should be reset.
+        settings.wheelSpeed /= 10;
+
         var shouldPrevent = false;
         $this.bind('mousewheel' + eventClassName, function (e, deprecatedDelta, deprecatedDeltaX, deprecatedDeltaY) {
-          var deltaX = e.deltaX || deprecatedDeltaX,
-              deltaY = e.deltaY || deprecatedDeltaY;
+          var deltaX = e.deltaX * e.deltaFactor || deprecatedDeltaX,
+              deltaY = e.deltaY * e.deltaFactor || deprecatedDeltaY;
 
           if (!settings.useBothWheelAxes) {
             // deltaX will only be used for horizontal scrolling and deltaY will
@@ -343,23 +349,23 @@
 
           switch (e.which) {
           case 37: // left
-            deltaX = -3;
+            deltaX = -30;
             break;
           case 38: // up
-            deltaY = 3;
+            deltaY = 30;
             break;
           case 39: // right
-            deltaX = 3;
+            deltaX = 30;
             break;
           case 40: // down
-            deltaY = -3;
+            deltaY = -30;
             break;
           case 33: // page up
-            deltaY = 9;
+            deltaY = 90;
             break;
           case 32: // space bar
           case 34: // page down
-            deltaY = -9;
+            deltaY = -90;
             break;
           case 35: // end
             deltaY = -containerHeight;
@@ -371,8 +377,8 @@
             return;
           }
 
-          $this.scrollTop($this.scrollTop() - (deltaY * settings.wheelSpeed));
-          $this.scrollLeft($this.scrollLeft() + (deltaX * settings.wheelSpeed));
+          $this.scrollTop($this.scrollTop() - deltaY);
+          $this.scrollLeft($this.scrollLeft() + deltaX);
 
           shouldPrevent = shouldPreventDefault(deltaX, deltaY);
           if (shouldPrevent) {