diff --git a/dist/js/bootstrap-multiselect.js b/dist/js/bootstrap-multiselect.js
index 9a50a18a..38be7fa2 100644
--- a/dist/js/bootstrap-multiselect.js
+++ b/dist/js/bootstrap-multiselect.js
@@ -48,7 +48,7 @@
         ko.bindingHandlers.multiselect = {
             after: ['options', 'value', 'selectedOptions', 'enable', 'disable'],
 
-            init: function(element, valueAccessor, allBindings, viewModel, bindingContext) {
+            init: function (element, valueAccessor, allBindings, viewModel, bindingContext) {
                 var $element = $(element);
                 var config = ko.toJS(valueAccessor());
 
@@ -58,9 +58,9 @@
                     var options = allBindings.get('options');
                     if (ko.isObservable(options)) {
                         ko.computed({
-                            read: function() {
+                            read: function () {
                                 options();
-                                setTimeout(function() {
+                                setTimeout(function () {
                                     var ms = $element.data('multiselect');
                                     if (ms)
                                         ms.updateOriginalOptions();//Not sure how beneficial this is.
@@ -79,9 +79,9 @@
                     var value = allBindings.get('value');
                     if (ko.isObservable(value)) {
                         ko.computed({
-                            read: function() {
+                            read: function () {
                                 value();
-                                setTimeout(function() {
+                                setTimeout(function () {
                                     $element.multiselect('refresh');
                                 }, 1);
                             },
@@ -96,9 +96,9 @@
                     var selectedOptions = allBindings.get('selectedOptions');
                     if (ko.isObservable(selectedOptions)) {
                         ko.computed({
-                            read: function() {
+                            read: function () {
                                 selectedOptions();
-                                setTimeout(function() {
+                                setTimeout(function () {
                                     $element.multiselect('refresh');
                                 }, 1);
                             },
@@ -144,12 +144,12 @@
                     }
                 }
 
-                ko.utils.domNodeDisposal.addDisposeCallback(element, function() {
+                ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
                     $element.multiselect('destroy');
                 });
             },
 
-            update: function(element, valueAccessor, allBindings, viewModel, bindingContext) {
+            update: function (element, valueAccessor, allBindings, viewModel, bindingContext) {
                 var $element = $(element);
                 var config = ko.toJS(valueAccessor());
 
@@ -236,9 +236,9 @@
              * @param {jQuery} select
              * @returns {String}
              */
-            buttonText: function(options, select) {
+            buttonText: function (options, select) {
                 if (this.disabledText.length > 0
-                        && (select.prop('disabled') || (options.length == 0 && this.disableIfEmpty)))  {
+                        && (select.prop('disabled') || (options.length == 0 && this.disableIfEmpty))) {
 
                     return this.disabledText;
                 }
@@ -264,7 +264,7 @@
                     var selected = '';
                     var delimiter = this.delimiterText;
 
-                    options.each(function() {
+                    options.each(function () {
                         var label = ($(this).attr('label') !== undefined) ? $(this).attr('label') : $(this).text();
                         selected += label + delimiter;
                     });
@@ -279,7 +279,7 @@
              * @param {jQuery} select
              * @returns {@exp;selected@call;substr}
              */
-            buttonTitle: function(options, select) {
+            buttonTitle: function (options, select) {
                 if (options.length === 0) {
                     return this.nonSelectedText;
                 }
@@ -294,7 +294,7 @@
                     return selected.substr(0, selected.length - this.delimiterText.length);
                 }
             },
-            checkboxName: function(option) {
+            checkboxName: function (option) {
                 return false; // no checkbox name
             },
             /**
@@ -303,7 +303,7 @@
              * @param {jQuery} element
              * @returns {String}
              */
-            optionLabel: function(element){
+            optionLabel: function (element) {
                 return $(element).attr('label') || $(element).text();
             },
             /**
@@ -312,7 +312,7 @@
              * @param {jQuery} element
              * @returns {String}
              */
-            optionClass: function(element) {
+            optionClass: function (element) {
                 return $(element).attr('class') || '';
             },
             /**
@@ -323,7 +323,7 @@
              * @param {jQuery} option
              * @param {Boolean} checked
              */
-            onChange : function(option, checked) {
+            onChange: function (option, checked) {
 
             },
             /**
@@ -331,7 +331,7 @@
              *
              * @param {jQuery} event
              */
-            onDropdownShow: function(event) {
+            onDropdownShow: function (event) {
 
             },
             /**
@@ -339,7 +339,7 @@
              *
              * @param {jQuery} event
              */
-            onDropdownHide: function(event) {
+            onDropdownHide: function (event) {
 
             },
             /**
@@ -347,7 +347,7 @@
              *
              * @param {jQuery} event
              */
-            onDropdownShown: function(event) {
+            onDropdownShown: function (event) {
 
             },
             /**
@@ -355,19 +355,19 @@
              *
              * @param {jQuery} event
              */
-            onDropdownHidden: function(event) {
+            onDropdownHidden: function (event) {
 
             },
             /**
              * Triggered on select all.
              */
-            onSelectAll: function() {
+            onSelectAll: function () {
 
             },
             /**
              * Triggered on deselect all.
              */
-            onDeselectAll: function() {
+            onDeselectAll: function () {
 
             },
             /**
@@ -376,7 +376,7 @@
              * @param {jQuery} $select
              * @param {jQuery} $container
              */
-            onInitialized: function($select, $container) {
+            onInitialized: function ($select, $container) {
 
             },
             /**
@@ -384,7 +384,7 @@
              *
              * @param {jQuery} $filter
              */
-            onFiltering: function($filter) {
+            onFiltering: function ($filter) {
 
             },
             enableHTML: false,
@@ -438,7 +438,7 @@
         /**
          * Builds the container of the multiselect.
          */
-        buildContainer: function() {
+        buildContainer: function () {
             this.$container = $(this.options.buttonContainer);
             this.$container.on('show.bs.dropdown', this.options.onDropdownShow);
             this.$container.on('hide.bs.dropdown', this.options.onDropdownHide);
@@ -449,7 +449,7 @@
         /**
          * Builds the button of the multiselect.
          */
-        buildButton: function() {
+        buildButton: function () {
             this.$button = $(this.options.templates.button).addClass(this.options.buttonClass);
             if (this.$select.attr('class') && this.options.inheritClass) {
                 this.$button.addClass(this.$select.attr('class'));
@@ -465,9 +465,9 @@
             // Manually add button width if set.
             if (this.options.buttonWidth && this.options.buttonWidth !== 'auto') {
                 this.$button.css({
-                    'width' : '100%', //this.options.buttonWidth,
-                    'overflow' : 'hidden',
-                    'text-overflow' : 'ellipsis'
+                    'width': '100%', //this.options.buttonWidth,
+                    'overflow': 'hidden',
+                    'text-overflow': 'ellipsis'
                 });
                 this.$container.css({
                     'width': this.options.buttonWidth
@@ -486,7 +486,7 @@
         /**
          * Builds the ul representing the dropdown menu.
          */
-        buildDropdown: function() {
+        buildDropdown: function () {
 
             // Build ul.
             this.$ul = $(this.options.templates.ul);
@@ -507,7 +507,7 @@
 
             if (this.options.dropUp) {
 
-                var height = Math.min(this.options.maxHeight, $('option[data-role!="divider"]', this.$select).length*26 + $('option[data-role="divider"]', this.$select).length*19 + (this.options.includeSelectAllOption ? 26 : 0) + (this.options.enableFiltering || this.options.enableCaseInsensitiveFiltering ? 44 : 0));
+                var height = Math.min(this.options.maxHeight, $('option[data-role!="divider"]', this.$select).length * 26 + $('option[data-role="divider"]', this.$select).length * 19 + (this.options.includeSelectAllOption ? 26 : 0) + (this.options.enableFiltering || this.options.enableCaseInsensitiveFiltering ? 44 : 0));
                 var moveCalc = height + 34;
 
                 this.$ul.css({
@@ -526,9 +526,9 @@
          *
          * Uses createDivider and createOptionValue to create the necessary options.
          */
-        buildDropdownOptions: function() {
+        buildDropdownOptions: function () {
 
-            this.$select.children().each($.proxy(function(index, element) {
+            this.$select.children().each($.proxy(function (index, element) {
 
                 var $element = $(element);
                 // Support optgroups and options without a group simultaneously.
@@ -557,13 +557,13 @@
             }, this));
 
             // Bind the change event on the dropdown elements.
-            $('li:not(.multiselect-group) input', this.$ul).on('change', $.proxy(function(event) {
+            $('li:not(.multiselect-group) input', this.$ul).on('change', $.proxy(function (event) {
                 var $target = $(event.target);
 
                 var checked = $target.prop('checked') || false;
                 var isSelectAllOption = $target.val() === this.options.selectAllValue;
 
-                // Apply or unapply the configured selected class.
+                // uApply or unapply the configured selected class.
                 if (this.options.selectedClass) {
                     if (checked) {
                         $target.closest('li')
@@ -635,25 +635,25 @@
                 this.$select.change();
                 this.updateButtonText();
 
-                if(this.options.preventInputChangeEvent) {
+                if (this.options.preventInputChangeEvent) {
                     return false;
                 }
             }, this));
 
-            $('li a', this.$ul).on('mousedown', function(e) {
+            $('li a', this.$ul).on('mousedown', function (e) {
                 if (e.shiftKey) {
                     // Prevent selecting text by Shift+click
                     return false;
                 }
             });
 
-            $('li a', this.$ul).on('touchstart click', $.proxy(function(event) {
+            $('li a', this.$ul).on('touchstart click', $.proxy(function (event) {
                 event.stopPropagation();
 
                 var $target = $(event.target);
 
                 if (event.shiftKey && this.options.multiple) {
-                    if($target.is("label")){ // Handles checkbox selection manually (see https://github.com/davidstutz/bootstrap-multiselect/issues/431)
+                    if ($target.is("label")) { // Handles checkbox selection manually (see https://github.com/davidstutz/bootstrap-multiselect/issues/431)
                         event.preventDefault();
                         $target = $target.find("input");
                         $target.prop("checked", !$target.prop("checked"));
@@ -697,7 +697,7 @@
                 }
 
                 // Remembers last clicked option
-                if($target.is("input") && !$target.closest("li").is(".multiselect-item")){
+                if ($target.is("input") && !$target.closest("li").is(".multiselect-item")) {
                     this.lastToggledInput = $target;
                 }
 
@@ -705,7 +705,7 @@
             }, this));
 
             // Keyboard support.
-            this.$container.off('keydown.multiselect').on('keydown.multiselect', $.proxy(function(event) {
+            this.$container.off('keydown.multiselect').on('keydown.multiselect', $.proxy(function (event) {
                 if ($('input[type="text"]', this.$container).is(':focus')) {
                     return;
                 }
@@ -726,7 +726,7 @@
                     if (event.keyCode === 38 && index > 0) {
                         index--;
                     }
-                    // Navigate down.
+                        // Navigate down.
                     else if (event.keyCode === 40 && index < $items.length - 1) {
                         index++;
                     }
@@ -750,7 +750,7 @@
             }, this));
 
             if (this.options.enableClickableOptGroups && this.options.multiple) {
-                $("li.multiselect-group input", this.$ul).on("change", $.proxy(function(event) {
+                $("li.multiselect-group input", this.$ul).on("change", $.proxy(function (event) {
                     event.stopPropagation();
 
                     var $target = $(event.target);
@@ -775,7 +775,7 @@
                         }
                     }
 
-                    $.each($inputs, $.proxy(function(index, input) {
+                    $.each($inputs, $.proxy(function (index, input) {
                         var value = $(input).val();
                         var $option = this.getOptionByValue(value);
 
@@ -807,23 +807,27 @@
             }
 
             if (this.options.enableCollapsibleOptGroups && this.options.multiple) {
-                $("li.multiselect-group .caret-container", this.$ul).on("click", $.proxy(function(event) {
+                $("li.multiselect-group .caret-container", this.$ul).on("click", $.proxy(function (event) {
                     var $li = $(event.target).closest('li');
                     var $inputs = $li.nextUntil("li.multiselect-group")
                             .not('.multiselect-filter-hidden');
 
+                    var $dropupplaceholder = $li.find("span.dropup-placeholder");
+
                     var visible = true;
-                    $inputs.each(function() {
+                    $inputs.each(function () {
                         visible = visible && $(this).is(':visible');
                     });
 
                     if (visible) {
                         $inputs.hide()
                             .addClass('multiselect-collapsible-hidden');
+                        $dropupplaceholder.addClass("dropup");
                     }
                     else {
                         $inputs.show()
                             .removeClass('multiselect-collapsible-hidden');
+                        $dropupplaceholder.removeClass("dropup");
                     }
                 }, this));
 
@@ -838,7 +842,7 @@
          *
          * @param {jQuery} element
          */
-        createOptionValue: function(element) {
+        createOptionValue: function (element) {
             var $element = $(element);
             if ($element.is(':selected')) {
                 $element.prop('selected', true);
@@ -906,7 +910,7 @@
          *
          * @param {jQuery} element
          */
-        createDivider: function(element) {
+        createDivider: function (element) {
             var $divider = $(this.options.templates.divider);
             this.$ul.append($divider);
         },
@@ -916,7 +920,7 @@
          *
          * @param {jQuery} group
          */
-        createOptgroup: function(group) {
+        createOptgroup: function (group) {
             var label = $(group).attr("label");
             var value = $(group).attr("value");
             var $li = $('<li class="multiselect-item multiselect-group"><a href="javascript:void(0);"><label><b></b></label></a></li>');
@@ -932,7 +936,7 @@
             }
 
             if (this.options.enableCollapsibleOptGroups && this.options.multiple) {
-                $('a', $li).append('<span class="caret-container"><b class="caret"></b></span>');
+                $('a', $li).append('<span class="caret-container"><span class="dropup-placeholder"><b class="caret"></b></span></span>');
             }
 
             if (this.options.enableClickableOptGroups && this.options.multiple) {
@@ -945,7 +949,7 @@
 
             this.$ul.append($li);
 
-            $("option", group).each($.proxy(function($, group) {
+            $("option", group).each($.proxy(function ($, group) {
                 this.createOptionValue(group);
             }, this))
         },
@@ -955,7 +959,7 @@
          *
          * Checks if a select all has already been created.
          */
-        buildSelectAll: function() {
+        buildSelectAll: function () {
             if (typeof this.options.selectAllValue === 'number') {
                 this.options.selectAllValue = this.options.selectAllValue.toString();
             }
@@ -1003,7 +1007,7 @@
         /**
          * Builds the filter.
          */
-        buildFilter: function() {
+        buildFilter: function () {
 
             // Build filter if filtering OR case insensitive filtering is enabled and the number of options exceeds (or equals) enableFilterLength.
             if (this.options.enableFiltering || this.options.enableCaseInsensitiveFiltering) {
@@ -1015,9 +1019,9 @@
                     $('input', this.$filter).attr('placeholder', this.options.filterPlaceholder);
 
                     // Adds optional filter clear button
-                    if(this.options.includeFilterClearBtn) {
+                    if (this.options.includeFilterClearBtn) {
                         var clearBtn = $(this.options.templates.filterClearBtn);
-                        clearBtn.on('click', $.proxy(function(event){
+                        clearBtn.on('click', $.proxy(function (event) {
                             clearTimeout(this.searchTimeout);
 
                             this.$filter.find('.multiselect-search').val('');
@@ -1035,24 +1039,24 @@
 
                     this.$ul.prepend(this.$filter);
 
-                    this.$filter.val(this.query).on('click', function(event) {
+                    this.$filter.val(this.query).on('click', function (event) {
                         event.stopPropagation();
-                    }).on('input keydown', $.proxy(function(event) {
+                    }).on('input keydown', $.proxy(function (event) {
                         // Cancel enter key default behaviour
                         if (event.which === 13) {
-                          event.preventDefault();
-                      }
+                            event.preventDefault();
+                        }
 
                         // This is useful to catch "keydown" events after the browser has updated the control.
                         clearTimeout(this.searchTimeout);
 
-                        this.searchTimeout = this.asyncFunction($.proxy(function() {
+                        this.searchTimeout = this.asyncFunction($.proxy(function () {
 
                             if (this.query !== event.target.value) {
                                 this.query = event.target.value;
 
                                 var currentGroup, currentGroupVisible;
-                                $.each($('li', this.$ul), $.proxy(function(index, element) {
+                                $.each($('li', this.$ul), $.proxy(function (index, element) {
                                     var value = $('input', element).length > 0 ? $('input', element).val() : "";
                                     var text = $('label', element).text();
 
@@ -1132,7 +1136,7 @@
         /**
          * Unbinds the whole plugin.
          */
-        destroy: function() {
+        destroy: function () {
             this.$container.remove();
             this.$select.show();
 
@@ -1205,8 +1209,8 @@
          * @param {Array} selectValues
          * @param {Boolean} triggerOnChange
          */
-        select: function(selectValues, triggerOnChange) {
-            if(!$.isArray(selectValues)) {
+        select: function (selectValues, triggerOnChange) {
+            if (!$.isArray(selectValues)) {
                 selectValues = [selectValues];
             }
 
@@ -1220,7 +1224,7 @@
                 var $option = this.getOptionByValue(value);
                 var $checkbox = this.getInputByValue(value);
 
-                if($option === undefined || $checkbox === undefined) {
+                if ($option === undefined || $checkbox === undefined) {
                     continue;
                 }
 
@@ -1271,8 +1275,8 @@
          * @param {Array} deselectValues
          * @param {Boolean} triggerOnChange
          */
-        deselect: function(deselectValues, triggerOnChange) {
-            if(!$.isArray(deselectValues)) {
+        deselect: function (deselectValues, triggerOnChange) {
+            if (!$.isArray(deselectValues)) {
                 deselectValues = [deselectValues];
             }
 
@@ -1286,7 +1290,7 @@
                 var $option = this.getOptionByValue(value);
                 var $checkbox = this.getInputByValue(value);
 
-                if($option === undefined || $checkbox === undefined) {
+                if ($option === undefined || $checkbox === undefined) {
                     continue;
                 }
 
@@ -1325,21 +1329,21 @@
             var allLis = $("li:not(.divider):not(.disabled):not(.multiselect-group)", this.$ul);
             var visibleLis = $("li:not(.divider):not(.disabled):not(.multiselect-group):not(.multiselect-filter-hidden):not(.multiselect-collapisble-hidden)", this.$ul).filter(':visible');
 
-            if(justVisible) {
-                $('input:enabled' , visibleLis).prop('checked', true);
+            if (justVisible) {
+                $('input:enabled', visibleLis).prop('checked', true);
                 visibleLis.addClass(this.options.selectedClass);
 
-                $('input:enabled' , visibleLis).each($.proxy(function(index, element) {
+                $('input:enabled', visibleLis).each($.proxy(function (index, element) {
                     var value = $(element).val();
                     var option = this.getOptionByValue(value);
                     $(option).prop('selected', true);
                 }, this));
             }
             else {
-                $('input:enabled' , allLis).prop('checked', true);
+                $('input:enabled', allLis).prop('checked', true);
                 allLis.addClass(this.options.selectedClass);
 
-                $('input:enabled' , allLis).each($.proxy(function(index, element) {
+                $('input:enabled', allLis).each($.proxy(function (index, element) {
                     var value = $(element).val();
                     var option = this.getOptionByValue(value);
                     $(option).prop('selected', true);
@@ -1370,21 +1374,21 @@
             var allLis = $("li:not(.divider):not(.disabled):not(.multiselect-group)", this.$ul);
             var visibleLis = $("li:not(.divider):not(.disabled):not(.multiselect-group):not(.multiselect-filter-hidden):not(.multiselect-collapisble-hidden)", this.$ul).filter(':visible');
 
-            if(justVisible) {
-                $('input[type="checkbox"]:enabled' , visibleLis).prop('checked', false);
+            if (justVisible) {
+                $('input[type="checkbox"]:enabled', visibleLis).prop('checked', false);
                 visibleLis.removeClass(this.options.selectedClass);
 
-                $('input[type="checkbox"]:enabled' , visibleLis).each($.proxy(function(index, element) {
+                $('input[type="checkbox"]:enabled', visibleLis).each($.proxy(function (index, element) {
                     var value = $(element).val();
                     var option = this.getOptionByValue(value);
                     $(option).prop('selected', false);
                 }, this));
             }
             else {
-                $('input[type="checkbox"]:enabled' , allLis).prop('checked', false);
+                $('input[type="checkbox"]:enabled', allLis).prop('checked', false);
                 allLis.removeClass(this.options.selectedClass);
 
-                $('input[type="checkbox"]:enabled' , allLis).each($.proxy(function(index, element) {
+                $('input[type="checkbox"]:enabled', allLis).each($.proxy(function (index, element) {
                     var value = $(element).val();
                     var option = this.getOptionByValue(value);
                     $(option).prop('selected', false);
@@ -1407,7 +1411,7 @@
          *
          * Rebuilds the dropdown, the filter and the select all option.
          */
-        rebuild: function() {
+        rebuild: function () {
             this.$ul.html('');
 
             // Important to distinguish between radios and checkboxes.
@@ -1439,7 +1443,7 @@
         /**
          * The provided data will be used to build the dropdown.
          */
-        dataprovider: function(dataprovider) {
+        dataprovider: function (dataprovider) {
 
             var groupCounter = 0;
             var $select = this.$select.empty();
@@ -1455,7 +1459,7 @@
                         disabled: !!option.disabled
                     });
 
-                    forEach(option.children, function(subOption) { // add children option tags
+                    forEach(option.children, function (subOption) { // add children option tags
                         var attributes = {
                             value: subOption.value,
                             label: subOption.label || subOption.value,
@@ -1465,10 +1469,10 @@
                         };
 
                         //Loop through attributes object and add key-value for each attribute
-                       for (var key in subOption.attributes) {
+                        for (var key in subOption.attributes) {
                             attributes['data-' + key] = subOption.attributes[key];
-                       }
-                         //Append original attributes + new data attributes to option
+                        }
+                        //Append original attributes + new data attributes to option
                         $tag.append($('<option/>').attr(attributes));
                     });
                 }
@@ -1484,7 +1488,7 @@
                     };
                     //Loop through attributes object and add key-value for each attribute
                     for (var key in option.attributes) {
-                      attributes['data-' + key] = option.attributes[key];
+                        attributes['data-' + key] = option.attributes[key];
                     }
                     //Append original attributes + new data attributes to option
                     $tag = $('<option/>').attr(attributes);
@@ -1501,7 +1505,7 @@
         /**
          * Enable the multiselect.
          */
-        enable: function() {
+        enable: function () {
             this.$select.prop('disabled', false);
             this.$button.prop('disabled', false)
                 .removeClass('disabled');
@@ -1510,7 +1514,7 @@
         /**
          * Disable the multiselect.
          */
-        disable: function() {
+        disable: function () {
             this.$select.prop('disabled', true);
             this.$button.prop('disabled', true)
                 .addClass('disabled');
@@ -1521,7 +1525,7 @@
          *
          * @param {Array} options
          */
-        setOptions: function(options) {
+        setOptions: function (options) {
             this.options = this.mergeOptions(options);
         },
 
@@ -1531,7 +1535,7 @@
          * @param {Array} options
          * @returns {Array}
          */
-        mergeOptions: function(options) {
+        mergeOptions: function (options) {
             return $.extend(true, {}, this.defaults, this.options, options);
         },
 
@@ -1540,33 +1544,40 @@
          *
          * @returns {Boolean}
          */
-        hasSelectAll: function() {
+        hasSelectAll: function () {
             return $('li.multiselect-all', this.$ul).length > 0;
         },
 
         /**
          * Update opt groups.
          */
-        updateOptGroups: function() {
+        updateOptGroups: function () {
             var $groups = $('li.multiselect-group', this.$ul)
             var selectedClass = this.options.selectedClass;
 
-            $groups.each(function() {
+            $groups.each(function () {
                 var $options = $(this).nextUntil('li.multiselect-group')
                     .not('.multiselect-filter-hidden')
                     .not('.disabled');
 
-                var checked = true;
-                $options.each(function() {
+                var hasAny = false;
+                var hasChecked = false;
+                var hasUnhecked = false;
+                $options.each(function () {
                     var $input = $('input', this);
-
+                    
+                    hasAny = true;
+                    
                     if (!$input.prop('checked')) {
-                        checked = false;
+                        hasUnhecked = true;
+                    }
+                    if ($input.prop('checked')) {
+                        hasChecked = true;
                     }
                 });
 
                 if (selectedClass) {
-                    if (checked) {
+                    if (hasChecked) {
                         $(this).addClass(selectedClass);
                     }
                     else {
@@ -1574,19 +1585,30 @@
                     }
                 }
 
-                $('input', this).prop('checked', checked);
+                if (hasChecked && !hasUnhecked) {
+                    $('input', this).prop('indeterminate', false);
+                    $('input', this).prop('checked', true);
+                }
+                else if ((hasUnhecked && !hasChecked) || !hasAny) {
+                    $('input', this).prop('indeterminate', false);
+                    $('input', this).prop('checked', false);
+                }
+                else {
+                    $('input', this).prop('indeterminate', true);
+                }
+
             });
         },
 
         /**
          * Updates the select all checkbox based on the currently displayed and selected checkboxes.
          */
-        updateSelectAll: function(notTriggerOnSelectAll) {
+        updateSelectAll: function (notTriggerOnSelectAll) {
             if (this.hasSelectAll()) {
                 var allBoxes = $("li:not(.multiselect-item):not(.multiselect-filter-hidden):not(.multiselect-group):not(.disabled) input:enabled", this.$ul);
                 var allBoxesLength = allBoxes.length;
                 var checkedBoxesLength = allBoxes.filter(":checked").length;
-                var selectAllLi  = $("li.multiselect-all", this.$ul);
+                var selectAllLi = $("li.multiselect-all", this.$ul);
                 var selectAllInput = selectAllLi.find("input");
 
                 if (checkedBoxesLength > 0 && checkedBoxesLength === allBoxesLength) {
@@ -1603,7 +1625,7 @@
         /**
          * Update the button text and its title based on the currently selected options.
          */
-        updateButtonText: function() {
+        updateButtonText: function () {
             var options = this.getSelected();
 
             // First update the displayed button text.
@@ -1623,7 +1645,7 @@
          *
          * @returns {jQUery}
          */
-        getSelected: function() {
+        getSelected: function () {
             return $('option', this.$select).filter(":selected");
         },
 
@@ -1668,25 +1690,25 @@
         /**
          * Used for knockout integration.
          */
-        updateOriginalOptions: function() {
+        updateOriginalOptions: function () {
             this.originalOptions = this.$select.clone()[0].options;
         },
 
-        asyncFunction: function(callback, timeout, self) {
+        asyncFunction: function (callback, timeout, self) {
             var args = Array.prototype.slice.call(arguments, 3);
-            return setTimeout(function() {
+            return setTimeout(function () {
                 callback.apply(self || window, args);
             }, timeout);
         },
 
-        setAllSelectedText: function(allSelectedText) {
+        setAllSelectedText: function (allSelectedText) {
             this.options.allSelectedText = allSelectedText;
             this.updateButtonText();
         }
     };
 
-    $.fn.multiselect = function(option, parameter, extraOptions) {
-        return this.each(function() {
+    $.fn.multiselect = function (option, parameter, extraOptions) {
+        return this.each(function () {
             var data = $(this).data('multiselect');
             var options = typeof option === 'object' && option;
 
@@ -1709,8 +1731,8 @@
 
     $.fn.multiselect.Constructor = Multiselect;
 
-    $(function() {
+    $(function () {
         $("select[data-role=multiselect]").multiselect();
     });
 
-}(window.jQuery);
+}(window.jQuery);
\ No newline at end of file