diff --git a/example/pubspec.lock b/example/pubspec.lock
index 1202879..54b1447 100644
--- a/example/pubspec.lock
+++ b/example/pubspec.lock
@@ -7,7 +7,7 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0"
+    version: "2.6.1"
   boolean_selector:
     dependency: transitive
     description:
@@ -87,7 +87,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "0.1.6"
+    version: "0.1.7"
   path:
     dependency: transitive
     description:
@@ -141,7 +141,7 @@ packages:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19"
+    version: "0.3.0"
   typed_data:
     dependency: transitive
     description:
@@ -157,4 +157,4 @@ packages:
     source: hosted
     version: "2.1.0"
 sdks:
-  dart: ">=2.12.0-0.0 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"
diff --git a/lib/multiselect_formfield.dart b/lib/multiselect_formfield.dart
index 7f2c823..6e11a5e 100644
--- a/lib/multiselect_formfield.dart
+++ b/lib/multiselect_formfield.dart
@@ -1,5 +1,6 @@
 library multiselect_formfield;
 
+import 'package:collection/collection.dart';
 import 'package:flutter/material.dart';
 import 'package:multiselect_formfield/multiselect_dialog.dart';
 
@@ -11,6 +12,7 @@ class MultiSelectFormField extends FormField<dynamic> {
   final List? dataSource;
   final String? textField;
   final String? valueField;
+  final Key? key;
   final Function? change;
   final Function? open;
   final Function? close;
@@ -32,8 +34,9 @@ class MultiSelectFormField extends FormField<dynamic> {
     FormFieldSetter<dynamic>? onSaved,
     FormFieldValidator<dynamic>? validator,
     dynamic initialValue,
-    bool autovalidate = false,
+    AutovalidateMode? autovalidate = AutovalidateMode.disabled,
     this.title = const Text('Title'),
+    this.key,
     this.hintWidget = const Text('Tap to select one or more'),
     this.required = false,
     this.errorText = 'Please select one or more options',
@@ -60,17 +63,18 @@ class MultiSelectFormField extends FormField<dynamic> {
     this.checkBoxCheckColor,
   }) : super(
           onSaved: onSaved,
+          key:key,
           validator: validator,
           initialValue: initialValue,
-          autovalidate: autovalidate,
+          autovalidateMode: autovalidate,
           builder: (FormFieldState<dynamic> state) {
             List<Widget> _buildSelectedOptions(state) {
               List<Widget> selectedOptions = [];
 
               if (state.value != null) {
                 state.value.forEach((item) {
-                  var existingItem = dataSource!.singleWhere(((itm) => itm[valueField] == item),
-                      orElse: () => null);
+                  var existingItem = dataSource!.firstWhereOrNull(((itm) => itm[valueField] == item));
+                  if (existingItem != null)
                   selectedOptions.add(Chip(
                     labelStyle: chipLabelStyle,
                     backgroundColor: chipBackGroundColor,
diff --git a/pubspec.lock b/pubspec.lock
index 9e492de..ad6d1df 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -7,7 +7,7 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0"
+    version: "2.6.1"
   boolean_selector:
     dependency: transitive
     description:
@@ -127,7 +127,7 @@ packages:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19"
+    version: "0.3.0"
   typed_data:
     dependency: transitive
     description:
@@ -143,4 +143,4 @@ packages:
     source: hosted
     version: "2.1.0"
 sdks:
-  dart: ">=2.12.0-0.0 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"
diff --git a/pubspec.yaml b/pubspec.yaml
index 8677820..0db96a9 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: multiselect_formfield
 description: A multi select form field using alert dialog to select multiple items with checkboxes and showing as chips.
-version: 0.1.6
+version: 0.1.7
 author: Carlos E. Torres <cetorres@cetorres.com>
 homepage: https://github.com/cetorres/multiselect_formfield