Overflow Scroll Issue in IE11

Example:


Actual Code::::

.scrollbar{
    height:400px;
    overflow-y: auto;   
}

The above code works for Firefox and Chrome but IE doesn't show up the scrollbar at all. Know u can update that css  to below.

Updated Code::::

.scrollbar{
    height:400px;
    overflow-y: auto; 
   -ms-overflow-style:auto;  
}