diff --git a/bower.json b/bower.json
index 1b741ef..b6b8eda 100644
--- a/bower.json
+++ b/bower.json
@@ -1,6 +1,6 @@
 {
   "name": "ng-expression-builder",
-  "version": "0.1.1",
+  "version": "0.1.2",
   "authors": [
     "Josh <joshua.bennett.chan@gmail.com>"
   ],
diff --git a/dist/expression-builder.js b/dist/expression-builder.js
index 1beef16..726e6d5 100644
--- a/dist/expression-builder.js
+++ b/dist/expression-builder.js
@@ -63,7 +63,7 @@ angular.module('expression-builder', ['ui.bootstrap'])
 						scope.booleanOperators = ['AND', 'OR', 'XOR'];
 					
 					if(scope.comparisonOperators === undefined)
-						scope.comparisonOperators = ['=', '<>', '<', '<=', '>', '>=', '[]'];
+						scope.comparisonOperators = ['=', '<>', '<', '<=', '>', '>=', '[]', '![]'];
 					
 					if(scope.leftOperandProvider)
 						scope.leftOperandProvider = scope.leftOperandProvider()
diff --git a/dist/expression-builder.min.js b/dist/expression-builder.min.js
index c6c4863..54d33c3 100644
--- a/dist/expression-builder.min.js
+++ b/dist/expression-builder.min.js
@@ -1 +1 @@
-angular.module("expression-builder",["ui.bootstrap"]).controller("ExpressionBuilderController",["$scope",function(o){o.addCondition=function(){o.conditions.push({})},o.addGroup=function(){o.conditions.push({conditions:[]})},o.remove=function(e){var n=o.conditions.indexOf(e);o.removeAt(n)},o.removeAt=function(e){o.conditions.splice(e,1)},o.getLeftOperands=function(e){return o.leftOperandProvider?o.leftOperandProvider(e):[]},o.getRightOperands=function(e){return o.rightOperandProvider?o.rightOperandProvider(e):[]}}]).directive("expressionBuilder",["$compile",function(o){return{restrict:"EA",controller:"ExpressionBuilderController",templateUrl:"templates/expressionbuilder.html",scope:{conditions:"=",booleanOperators:"=?",comparisonOperators:"=?",leftOperandProvider:"&",rightOperandProvider:"&"},compile:function(e){var n,r=e.contents().remove();return function(e,i){angular.isUndefined(n)&&(n=o(r)),n(e,function(o){i.append(o)}),void 0===e.booleanOperators&&(e.booleanOperators=["AND","OR","XOR"]),void 0===e.comparisonOperators&&(e.comparisonOperators=["=","<>","<","<=",">",">=","[]"]),e.leftOperandProvider&&(e.leftOperandProvider=e.leftOperandProvider()),e.rightOperandProvider&&(e.rightOperandProvider=e.rightOperandProvider())}}}}]),angular.module("expression-builder").run(["$templateCache",function(o){o.put("templates/expressionbuilder.html",'<div class=condition-builder><div ng-repeat="c in conditions"><div ng-if="$index != 0" class="form-inline bool-op"><select class="form-control input-sm" ng-options="o as o for o in booleanOperators" ng-model=c.bool></select></div><div ng-if=c.conditions class=condition-group><div class=pull-right><button class="btn btn-danger btn-sm" ng-click=removeAt($index)>&times;</button></div><expression-builder conditions=c.conditions boolean-operators=booleanOperators comparison-operators=comparisonOperators left-operand-provider=leftOperandProvider right-operand-provider=rightOperandProvider></expression-builder></div><div ng-if=!c.conditions class=form-inline><div class=form-group-sm><input class=form-control ng-model=c.leftOperand placeholder="Left Operand" typeahead="operand for operand in getLeftOperands($viewValue)"><select class=form-control ng-model=c.comparison ng-options="o as o for o in comparisonOperators"></select><input class=form-control ng-model=c.rightOperand placeholder="Right Operand" typeahead="operand for operand in getRightOperands($viewValue)"> <button class="btn btn-danger btn-sm" ng-click=removeAt($index)>&times;</button></div></div></div><div class=condition-group-button-row><button class="btn btn-success btn-sm" ng-click=addCondition()>Add Condition</button> <button class="btn btn-success btn-sm" ng-click=addGroup()>Add Group</button></div></div>')}]);
\ No newline at end of file
+angular.module("expression-builder",["ui.bootstrap"]).controller("ExpressionBuilderController",["$scope",function(o){o.addCondition=function(){o.conditions.push({})},o.addGroup=function(){o.conditions.push({conditions:[]})},o.remove=function(e){var n=o.conditions.indexOf(e);o.removeAt(n)},o.removeAt=function(e){o.conditions.splice(e,1)},o.getLeftOperands=function(e){return o.leftOperandProvider?o.leftOperandProvider(e):[]},o.getRightOperands=function(e){return o.rightOperandProvider?o.rightOperandProvider(e):[]}}]).directive("expressionBuilder",["$compile",function(o){return{restrict:"EA",controller:"ExpressionBuilderController",templateUrl:"templates/expressionbuilder.html",scope:{conditions:"=",booleanOperators:"=?",comparisonOperators:"=?",leftOperandProvider:"&",rightOperandProvider:"&"},compile:function(e){var n,r=e.contents().remove();return function(e,i){angular.isUndefined(n)&&(n=o(r)),n(e,function(o){i.append(o)}),void 0===e.booleanOperators&&(e.booleanOperators=["AND","OR","XOR"]),void 0===e.comparisonOperators&&(e.comparisonOperators=["=","<>","<","<=",">",">=","[]","![]"]),e.leftOperandProvider&&(e.leftOperandProvider=e.leftOperandProvider()),e.rightOperandProvider&&(e.rightOperandProvider=e.rightOperandProvider())}}}}]),angular.module("expression-builder").run(["$templateCache",function(o){o.put("templates/expressionbuilder.html",'<div class=condition-builder><div ng-repeat="c in conditions"><div ng-if="$index != 0" class="form-inline bool-op"><select class="form-control input-sm" ng-options="o as o for o in booleanOperators" ng-model=c.bool></select></div><div ng-if=c.conditions class=condition-group><div class=pull-right><button class="btn btn-danger btn-sm" ng-click=removeAt($index)>&times;</button></div><expression-builder conditions=c.conditions boolean-operators=booleanOperators comparison-operators=comparisonOperators left-operand-provider=leftOperandProvider right-operand-provider=rightOperandProvider></expression-builder></div><div ng-if=!c.conditions class=form-inline><div class=form-group-sm><input class=form-control ng-model=c.leftOperand placeholder="Left Operand" typeahead="operand for operand in getLeftOperands($viewValue)"><select class=form-control ng-model=c.comparison ng-options="o as o for o in comparisonOperators"></select><input class=form-control ng-model=c.rightOperand placeholder="Right Operand" typeahead="operand for operand in getRightOperands($viewValue)"> <button class="btn btn-danger btn-sm" ng-click=removeAt($index)>&times;</button></div></div></div><div class=condition-group-button-row><button class="btn btn-success btn-sm" ng-click=addCondition()>Add Condition</button> <button class="btn btn-success btn-sm" ng-click=addGroup()>Add Group</button></div></div>')}]);
\ No newline at end of file
diff --git a/package.json b/package.json
index 2edf040..4120143 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ng-expression-builder",
-  "version": "0.1.1",
+  "version": "0.1.2",
   "description": "",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
diff --git a/src/js/expression-builder.js b/src/js/expression-builder.js
index b5d6e2c..8df753f 100644
--- a/src/js/expression-builder.js
+++ b/src/js/expression-builder.js
@@ -63,7 +63,7 @@ angular.module('expression-builder', ['ui.bootstrap'])
 						scope.booleanOperators = ['AND', 'OR', 'XOR'];
 					
 					if(scope.comparisonOperators === undefined)
-						scope.comparisonOperators = ['=', '<>', '<', '<=', '>', '>=', '[]'];
+						scope.comparisonOperators = ['=', '<>', '<', '<=', '>', '>=', '[]', '![]'];
 					
 					if(scope.leftOperandProvider)
 						scope.leftOperandProvider = scope.leftOperandProvider()