diff --git a/Gruntfile.js b/Gruntfile.js
index bdb40cc2..cfb31c00 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -22,8 +22,8 @@ module.exports = function(grunt) {
             'src/public.js',
             'src/data.js',
             'src/template.js',
-            'src/model.js',
             'src/utils.js',
+            'src/model.js',
             'src/jquery.js'
         ],
         js_files_for_standalone: [
diff --git a/examples/index.html b/examples/index.html
index ff6592b0..369c9eda 100644
--- a/examples/index.html
+++ b/examples/index.html
@@ -133,8 +133,8 @@ <h3>Output</h3>
 <script src="../src/public.js"></script>
 <script src="../src/data.js"></script>
 <script src="../src/template.js"></script>
-<script src="../src/model.js"></script>
 <script src="../src/utils.js"></script>
+<script src="../src/model.js"></script>
 <script src="../src/jquery.js"></script>
 <script src="../src/plugins/bt-checkbox/plugin.js"></script>
 <script src="../src/plugins/bt-selectpicker/plugin.js"></script>
diff --git a/src/model.js b/src/model.js
index af13aac7..a397c98f 100644
--- a/src/model.js
+++ b/src/model.js
@@ -64,44 +64,6 @@ $.extend(Model.prototype, /** @lends Model.prototype */ {
     }
 });
 
-/**
- * Defines properties on an Node prototype with getter and setter.<br>
- *     Update events are emitted in the setter through root Model (if any).<br>
- *     The object must have a `__` object, non enumerable property to store values.
- * @param {function} obj
- * @param {string[]} fields
- */
-Model.defineModelProperties = function(obj, fields) {
-    fields.forEach(function(field) {
-        Object.defineProperty(obj.prototype, field, {
-            enumerable: true,
-            get: function() {
-                return this.__[field];
-            },
-            set: function(value) {
-                var previousValue = (this.__[field] !== null && typeof this.__[field] == 'object') ?
-                    $.extend({}, this.__[field]) :
-                    this.__[field];
-
-                this.__[field] = value;
-
-                if (this.model !== null) {
-                    /**
-                     * After a value of the model changed
-                     * @event model:update
-                     * @memberof Model
-                     * @param {Node} node
-                     * @param {string} field
-                     * @param {*} value
-                     * @param {*} previousValue
-                     */
-                    this.model.trigger('update', this, field, value, previousValue);
-                }
-            }
-        });
-    });
-};
-
 
 /**
  * Root abstract object
@@ -177,7 +139,7 @@ var Node = function(parent, $el) {
     this.parent = parent;
 };
 
-Model.defineModelProperties(Node, ['level', 'error', 'data', 'flags']);
+Utils.defineModelProperties(Node, ['level', 'error', 'data', 'flags']);
 
 Object.defineProperty(Node.prototype, 'parent', {
     enumerable: true,
@@ -340,7 +302,7 @@ var Group = function(parent, $el) {
 Group.prototype = Object.create(Node.prototype);
 Group.prototype.constructor = Group;
 
-Model.defineModelProperties(Group, ['condition']);
+Utils.defineModelProperties(Group, ['condition']);
 
 /**
  * Removes group's content
@@ -561,7 +523,7 @@ var Rule = function(parent, $el) {
 Rule.prototype = Object.create(Node.prototype);
 Rule.prototype.constructor = Rule;
 
-Model.defineModelProperties(Rule, ['filter', 'operator', 'value']);
+Utils.defineModelProperties(Rule, ['filter', 'operator', 'value']);
 
 /**
  * Checks if this Node is the root
diff --git a/src/plugins/not-group/plugin.js b/src/plugins/not-group/plugin.js
index 6596a817..da6f98b0 100644
--- a/src/plugins/not-group/plugin.js
+++ b/src/plugins/not-group/plugin.js
@@ -104,7 +104,7 @@ QueryBuilder.define('not-group', function(options) {
  * @memberof Group
  * @instance
  */
-Model.defineModelProperties(Group, ['not']);
+Utils.defineModelProperties(Group, ['not']);
 
 QueryBuilder.selectors.group_not = QueryBuilder.selectors.group_header + ' [data-not=group]';
 
diff --git a/src/utils.js b/src/utils.js
index 8f6150f2..94af0956 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -202,3 +202,41 @@ Utils.groupSort = function(items, key) {
 
     return newItems;
 };
+
+/**
+ * Defines properties on an Node prototype with getter and setter.<br>
+ *     Update events are emitted in the setter through root Model (if any).<br>
+ *     The object must have a `__` object, non enumerable property to store values.
+ * @param {function} obj
+ * @param {string[]} fields
+ */
+Utils.defineModelProperties = function(obj, fields) {
+    fields.forEach(function(field) {
+        Object.defineProperty(obj.prototype, field, {
+            enumerable: true,
+            get: function() {
+                return this.__[field];
+            },
+            set: function(value) {
+                var previousValue = (this.__[field] !== null && typeof this.__[field] == 'object') ?
+                    $.extend({}, this.__[field]) :
+                    this.__[field];
+
+                this.__[field] = value;
+
+                if (this.model !== null) {
+                    /**
+                     * After a value of the model changed
+                     * @event model:update
+                     * @memberof Model
+                     * @param {Node} node
+                     * @param {string} field
+                     * @param {*} value
+                     * @param {*} previousValue
+                     */
+                    this.model.trigger('update', this, field, value, previousValue);
+                }
+            }
+        });
+    });
+};
diff --git a/tests/index.html b/tests/index.html
index 343c9210..3af96d4d 100644
--- a/tests/index.html
+++ b/tests/index.html
@@ -38,8 +38,8 @@
   <script src="../src/public.js" data-cover></script>
   <script src="../src/data.js" data-cover></script>
   <script src="../src/template.js" data-cover></script>
-  <script src="../src/model.js" data-cover></script>
   <script src="../src/utils.js" data-cover></script>
+  <script src="../src/model.js" data-cover></script>
   <script src="../src/jquery.js" data-cover></script>
   <script src="../src/plugins/bt-checkbox/plugin.js" data-cover></script>
   <script src="../src/plugins/bt-selectpicker/plugin.js" data-cover></script>