diff --git a/helfi_media_map.module b/helfi_media_map.module
index dd9589b..700b9d2 100644
--- a/helfi_media_map.module
+++ b/helfi_media_map.module
@@ -17,3 +17,15 @@ function helfi_media_map_entity_bundle_field_info_alter(&$fields, EntityTypeInte
     }
   }
 }
+
+/**
+ * Implements hook_theme().
+ */
+function helfi_media_map_theme($existing, $type, $theme, $path) {
+  return [
+    'helfi_media_map' => [
+      'variables' => ['link' => NULL, 'iframe' => NULL],
+      'template' => 'helfi-media-map'
+    ],
+  ];
+}
diff --git a/src/Plugin/Field/FieldFormatter/MediaMapFormatter.php b/src/Plugin/Field/FieldFormatter/MediaMapFormatter.php
index 238583c..4f30928 100644
--- a/src/Plugin/Field/FieldFormatter/MediaMapFormatter.php
+++ b/src/Plugin/Field/FieldFormatter/MediaMapFormatter.php
@@ -7,6 +7,7 @@
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Field\FormatterBase;
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Url;
 use Drupal\helfi_media_map\UrlParserTrait;
 
 /**
@@ -51,7 +52,7 @@ public function settingsForm(array $form, FormStateInterface $form_state) : arra
   /**
    * {@inheritdoc}
    */
-  public function viewElements(FieldItemListInterface $items, $langcode) {
+  public function viewElements(FieldItemListInterface $items, $langcode) :array {
     $element = [];
 
     foreach ($items as $delta => $item) {
@@ -59,7 +60,8 @@ public function viewElements(FieldItemListInterface $items, $langcode) {
       $link = $this->getMapUrl($uri);
 
       $element[$delta] = [
-        'iframe' => [
+        '#theme' => 'helfi_media_map',
+        '#iframe' => [
           '#type' => 'html_tag',
           '#tag' => 'iframe',
           '#value' => '',
@@ -72,14 +74,11 @@ public function viewElements(FieldItemListInterface $items, $langcode) {
       ];
 
       if ($link_title = $this->getSetting('link_title')) {
-        $element[$delta]['link'] = [
-          '#type' => 'html_tag',
-          '#tag' => 'a',
-          '#value' => $link_title,
-          '#attributes' => [
-            'href' => $link,
-            'target' => '_blank',
-          ],
+        $element[$delta]['#link'] = [
+          '#type' => 'link',
+          '#title' => $link_title,
+          '#url' => Url::fromUri($link),
+          '#attributes' => ['target' => '_blank'],
         ];
       }
     }
diff --git a/templates/helfi-media-map.html.twig b/templates/helfi-media-map.html.twig
new file mode 100644
index 0000000..ade7e89
--- /dev/null
+++ b/templates/helfi-media-map.html.twig
@@ -0,0 +1,2 @@
+{{ iframe }}
+{{ link }}