diff --git a/Toolkit.js b/Toolkit.js
index 9e37352..e4e9dca 100644
--- a/Toolkit.js
+++ b/Toolkit.js
@@ -304,6 +304,31 @@ Ext.define('Proxmox.form.field.Text', {
     },
 });
 
+// this should be fixed with ExtJS 6.0.2
+// make mousescrolling work in firefox in the containers overflowhandler
+Ext.define(null, {
+    override: 'Ext.layout.container.boxOverflow.Scroller',
+
+    createWheelListener: function() {
+	var me = this;
+	if (Ext.isFirefox) {
+	    me.wheelListener = me.layout.innerCt.on('wheel', me.onMouseWheelFirefox, me, {destroyable: true});
+	} else {
+	    me.wheelListener = me.layout.innerCt.on('mousewheel', me.onMouseWheel, me, {destroyable: true});
+	}
+    },
+
+    // special wheel handler for firefox. differs from the default onMouseWheel
+    // handler by using deltaY instead of wheelDeltaY and no normalizing,
+    // because it is already
+    onMouseWheelFirefox: function(e) {
+	e.stopEvent();
+	var delta = e.browserEvent.deltaY || 0;
+	this.scrollBy(delta * this.wheelIncrement, false);
+    }
+
+});
+
 // force alert boxes to be rendered with an Error Icon
 // since Ext.Msg is an object and not a prototype, we need to override it
 // after the framework has been initiated