diff --git a/templates/viewer.html b/templates/viewer.html
index e9ce6d3..419824c 100644
--- a/templates/viewer.html
+++ b/templates/viewer.html
@@ -251,15 +251,15 @@
         </div>
         <div class="col col-auto pt-1">
             <button class="btn btn-outline-info p-1" title="Rotate by 90 degrees" onClick="Transform(90)">
-		<img src="{{url_for('internal', filename='rot90.png')}}" height="32" onMouseOver="this.src='{{url_for('internal', filename='rot90-invert.png')}}'" 
+		<img src="{{url_for('internal', filename='rot90.png')}}" width="32" height="32" onMouseOver="this.src='{{url_for('internal', filename='rot90-invert.png')}}'" 
 		    onMouseOut="this.src='{{url_for('internal', filename='rot90.png')}}'" />
             </button>
             <button class="btn btn-outline-info p-1" title="Rotate by 180 degrees" onClick="Transform(180)">
-		<img src="{{url_for('internal', filename='rot180.png')}}" height="32" onMouseOver="this.src='{{url_for('internal', filename='rot180-invert.png')}}'"
+		<img src="{{url_for('internal', filename='rot180.png')}}" width="32" height="32" onMouseOver="this.src='{{url_for('internal', filename='rot180-invert.png')}}'"
 		    onMouseOut="this.src='{{url_for('internal', filename='rot180.png')}}'" />
             </button>
             <button class="btn btn-outline-info p-1" title="Rotate by 270 degrees" onClick="Transform(270)">
-		<img src="{{url_for('internal', filename='rot270.png')}}" height="32" onMouseOver="this.src='{{url_for('internal', filename='rot270-invert.png')}}'"
+		<img src="{{url_for('internal', filename='rot270.png')}}" width="32" height="32" onMouseOver="this.src='{{url_for('internal', filename='rot270-invert.png')}}'"
 		    onMouseOut="this.src='{{url_for('internal', filename='rot270.png')}}'" />
             </button>
             <button class="btn btn-outline-info p-1" title="Flip horizontally" onClick="Transform('fliph')">