diff --git a/src/ReadonlyTagField.php b/src/ReadonlyTagField.php
index 505a2ad..2148d55 100644
--- a/src/ReadonlyTagField.php
+++ b/src/ReadonlyTagField.php
@@ -27,7 +27,8 @@ class ReadonlyTagField extends TagField
     {
         $options = array();
 
-        foreach ($this->getOptions()->filter('Selected', true) as $option) {
+        // only get the selected options
+        foreach ($this->getOptions(true) as $option) {
             $options[] = $option->Title;
         }
 
diff --git a/tests/TagFieldTest.php b/tests/TagFieldTest.php
index 4ebfc8d..faf985f 100755
--- a/tests/TagFieldTest.php
+++ b/tests/TagFieldTest.php
@@ -408,6 +408,22 @@ class TagFieldTest extends SapphireTest
         $field->setTitleField('Name');
         $readOnlyField = $field->performReadonlyTransformation();
         $this->assertEquals('Name', $readOnlyField->getTitleField());
+
+        // Also check Field options
+        $field = new TagField('Tags', '', TagFieldTestBlogTag::get());
+        $field->setTitleField('Title');
+        $field->setValue(['Tag1']);
+
+        // When not read only (and not lazy-loading) all source options are returned
+        $htmlText = $field->Field();
+        $this->assertStringContainsString('Tag1', $htmlText);
+        $this->assertStringContainsString('222', $htmlText);
+
+        // When read only mode, only selected options are returned
+        $readOnlyField = $field->performReadonlyTransformation();
+        $htmlText = $readOnlyField->Field();
+        $this->assertStringContainsString('Tag1', $htmlText);
+        $this->assertStringNotContainsString('222', $htmlText);
     }
 
     public function testItDisplaysWithSelectedValuesFromDataList()