diff --git a/index.html b/index.html
index a9b79053..dc6a92f1 100644
--- a/index.html
+++ b/index.html
@@ -344,7 +344,15 @@
 
       var textEmailFilter = new Choices('#choices-text-email-filter', {
         editItems: true,
-        regexFilter: /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/,
+        addItemFilterFn: (value) => {
+          if (!value) {
+            return false;
+          }
+
+          const regex = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/
+          const expression = new RegExp(regex.source, 'i');
+          return expression.test(value);
+        },
       }).setValue(['joe@bloggs.com']);
 
       var textDisabled = new Choices('#choices-text-disabled', {
diff --git a/test/select-multiple.html b/test/select-multiple.html
index a2a76212..2b0b4a81 100644
--- a/test/select-multiple.html
+++ b/test/select-multiple.html
@@ -33,7 +33,6 @@
           <label for="choices-basic">Basic</label>
           <button class="open-dropdown push-bottom">Open dropdown</button>
           <button class="close-dropdown push-bottom">Close dropdown</button>
-          <button class="toggle-dropdown push-bottom">Toggle dropdown</button>
           <button class="disable push-bottom">Disable</button>
           <button class="enable push-bottom">Enable</button>
           <select class="form-control" name="choices-basic" id="choices-basic" multiple>
@@ -216,10 +215,6 @@
           choicesBasic.hideDropdown();
         });
 
-        document.querySelector('button.toggle-dropdown').addEventListener('click', () => {
-          choicesBasic.toggleDropdown();
-        });
-
         document.querySelector('button.disable').addEventListener('click', () => {
           choicesBasic.disable();
         });
diff --git a/test/select-one.html b/test/select-one.html
index 6f9e5496..b78177c5 100644
--- a/test/select-one.html
+++ b/test/select-one.html
@@ -33,7 +33,6 @@
           <label for="choices-basic">Basic</label>
           <button class="open-dropdown push-bottom">Open dropdown</button>
           <button class="close-dropdown push-bottom">Close dropdown</button>
-          <button class="toggle-dropdown push-bottom">Toggle dropdown</button>
           <button class="disable push-bottom">Disable</button>
           <button class="enable push-bottom">Enable</button>
           <select class="form-control" name="choices-basic" id="choices-basic">
@@ -220,10 +219,6 @@
           choicesBasic.hideDropdown();
         });
 
-        document.querySelector('button.toggle-dropdown').addEventListener('click', () => {
-          choicesBasic.toggleDropdown(true);
-        });
-
         document.querySelector('button.disable').addEventListener('click', () => {
           choicesBasic.disable();
         });
diff --git a/test/text.html b/test/text.html
index dd7427f8..1d4ea24e 100644
--- a/test/text.html
+++ b/test/text.html
@@ -54,9 +54,9 @@
           <input class="form-control" id="choices-input-limit" type="text">
         </div>
 
-        <div data-test-hook="regex-filter">
-          <label for="choices-regex-filter">Regex filter</label>
-          <input class="form-control" id="choices-regex-filter" type="text">
+        <div data-test-hook="add-item-filter">
+          <label for="choices-add-item-filter">Add item filter</label>
+          <input class="form-control" id="choices-add-item-filter" type="text">
         </div>
 
         <div data-test-hook="adding-items-disabled">
@@ -64,11 +64,6 @@
           <input class="form-control" id="choices-adding-items-disabled" type="text">
         </div>
 
-        <div data-test-hook="add-item-callback">
-          <label for="choices-add-item-callback">Callback on Add Item</label>
-          <input class="form-control" id="choices-add-item-callback" type="text">
-        </div>
-
         <div data-test-hook="disabled-via-attr">
           <label for="choices-disabled-via-attr">Disabled via attribute</label>
           <input class="form-control" id="choices-disabled-via-attr" type="text" disabled>
@@ -117,20 +112,19 @@
           maxItemCount: 5,
         });
 
-        new Choices('#choices-regex-filter', {
-          regexFilter: /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/,
+        new Choices('#choices-add-item-filter', {
+          addItems: true,
+          addItemFilterFn: (value) => {
+            const regex = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/
+            const expression = new RegExp(regex.source, 'i');
+            return expression.test(value);
+          },
         });
 
         new Choices('#choices-adding-items-disabled', {
           addItems: false,
         });
 
-        new Choices('#choices-add-item-callback', {
-          addItemFilter: function (value) {
-            return (value !== 'test')
-          }
-        });
-
         new Choices('#choices-disabled-via-attr');
 
         new Choices('#choices-prepend-append', {