diff --git a/module/assets/js/contao-leaflet.js b/module/assets/js/contao-leaflet.js
index a678a6a..51f1240 100644
--- a/module/assets/js/contao-leaflet.js
+++ b/module/assets/js/contao-leaflet.js
@@ -1,10 +1,31 @@
 L.Contao = L.Class.extend( {
     includes: L.Mixin.Events,
 
+    /**
+     * The map registry.
+     */
     maps: {},
 
+    /**
+     * The icons registry.
+     */
     icons: {},
 
+    /**
+     * Initialize Contao leaflet integration.
+     */
+    initialize: function() {
+        L.Icon.Default.imagePath = 'assets/leaflet/libs/leaflet/images';
+    },
+
+    /**
+     * Add map to map registry.
+     *
+     * @param id  The map id.
+     * @param map The map object.
+     *
+     * @returns {L.Contao}
+     */
     addMap: function (id, map) {
         this.maps[id] = map;
 
@@ -13,6 +34,13 @@ L.Contao = L.Class.extend( {
         return this;
     },
 
+    /**
+     * Get a map from the icon map. Returns null if not set.
+     *
+     * @param id The mapobject
+     *
+     * @returns {L.Map}|{*}
+     */
     getMap: function (id) {
         if (typeof (this.maps[id]) === 'undefined') {
             return null;
@@ -21,6 +49,14 @@ L.Contao = L.Class.extend( {
         return this.maps[id];
     },
 
+    /**
+     * Add an icon to the icon registry.
+     *
+     * @param id   The icon id.
+     * @param icon The icon object.
+     *
+     * @returns {L.Contao}
+     */
     addIcon: function(id, icon) {
         this.icons[id] = icon;
         this.fire('icon:added', { id: id, icon: icon});
@@ -28,6 +64,27 @@ L.Contao = L.Class.extend( {
         return this;
     },
 
+    /**
+     * Load icon definitions.
+     *
+     * @param icons List of icon definitions.
+     *
+     * @return void
+     */
+    loadIcons: function(icons) {
+        for (var i = 0; i < icons.length; i++) {
+            var icon = L[icons[i].type](icons[i].options);
+            this.addIcon(icons[i].id, icon);
+        }
+    },
+
+    /**
+     * Get an icon by its id.
+     *
+     * @param id Icon id.
+     *
+     * @returns {L.Icon}|{L.DivIcon}|{*}
+     */
     getIcon: function(id) {
         if (typeof (this.icons[id]) === 'undefined') {
             return null;
@@ -36,6 +93,14 @@ L.Contao = L.Class.extend( {
         return this.icons[id];
     },
 
+    /**
+     * Point to layer callback. Adds a geo json point to the layer.
+     *
+     * @param feature The geo json feature.
+     * @param latlng  The converted latlng.
+     *
+     * @returns {L.Marker}|{*}
+     */
     pointToLayer: function(feature, latlng) {
         var marker = L.marker(latlng, feature.properties.options);
 
@@ -53,6 +118,12 @@ L.Contao = L.Class.extend( {
         return marker;
     },
 
+    /**
+     * Apply feature methods.
+     *
+     * @param obj
+     * @param feature
+     */
     applyFeatureMethods: function(obj, feature) {
         if (feature.properties && feature.properties.methods) {
             for (var i=0; i < feature.properties.methods.length; i++) {
@@ -64,6 +135,4 @@ L.Contao = L.Class.extend( {
     }
 });
 
-L.Icon.Default.imagePath = 'assets/leaflet/libs/leaflet/images';
-
 window.ContaoLeaflet = new L.Contao();
diff --git a/src/Netzmacht/Contao/Leaflet/Mapper/Type/ImageIconMapper.php b/src/Netzmacht/Contao/Leaflet/Mapper/Type/ImageIconMapper.php
index 6bccafd..5ea701e 100644
--- a/src/Netzmacht/Contao/Leaflet/Mapper/Type/ImageIconMapper.php
+++ b/src/Netzmacht/Contao/Leaflet/Mapper/Type/ImageIconMapper.php
@@ -34,6 +34,17 @@ class ImageIconMapper extends AbstractIconMapper
      */
     protected static $type = 'image';
 
+    /**
+     * {@inheritdoc}
+     */
+    protected function initialize()
+    {
+        $this->addConditionalOption('className');
+    }
+
+    /**
+     * {@inheritdoc}
+     */
     protected function buildConstructArguments(\Model $model, DefinitionMapper $mapper, LatLngBounds $bounds = null)
     {
         $arguments = parent::buildConstructArguments($model, $mapper, $bounds);
@@ -49,7 +60,9 @@ class ImageIconMapper extends AbstractIconMapper
         return $arguments;
     }
 
-
+    /**
+     * {@inheritdoc}
+     */
     protected function doBuild(
         Definition $definition,
         \Model $model,
@@ -63,8 +76,12 @@ class ImageIconMapper extends AbstractIconMapper
     }
 
     /**
-     * @param Icon      $definition
-     * @param IconModel $model
+     * Add icon image.
+     *
+     * @param Icon      $definition The icon definition.
+     * @param IconModel $model      The model.
+     *
+     * @return void
      */
     private function addIcon(Icon $definition, IconModel $model)
     {
@@ -82,7 +99,7 @@ class ImageIconMapper extends AbstractIconMapper
                 }
 
                 if (!$model->popupAnchor) {
-                    $definition->setPopupAnchor(array(0, 10 - $file->height));
+                    $definition->setPopupAnchor(array(0, 8 - $file->height));
                 }
             }
         }
@@ -100,6 +117,14 @@ class ImageIconMapper extends AbstractIconMapper
         }
     }
 
+    /**
+     * Add shadow if defined.
+     *
+     * @param Icon      $definition The icon definition.
+     * @param IconModel $model      The model.
+     *
+     * @return void
+     */
     private function addShadow(Icon $definition, $model)
     {
         if ($model->shadowImage) {
diff --git a/src/Netzmacht/Contao/Leaflet/Model/IconModel.php b/src/Netzmacht/Contao/Leaflet/Model/IconModel.php
index cae83a9..64c635c 100644
--- a/src/Netzmacht/Contao/Leaflet/Model/IconModel.php
+++ b/src/Netzmacht/Contao/Leaflet/Model/IconModel.php
@@ -17,6 +17,9 @@ namespace Netzmacht\Contao\Leaflet\Model;
  * @property mixed|null iconAnchor
  * @property mixed|null popupAnchor
  * @property mixed|null iconRetinaImage
+ * @property mixed|null shadowAnchor
+ * @property mixed|null shadowRetinaImage
+ * @property mixed|null shadowImage
  */
 class IconModel extends \Model
 {
diff --git a/src/Netzmacht/Contao/Leaflet/Subscriber/BootSubscriber.php b/src/Netzmacht/Contao/Leaflet/Subscriber/BootSubscriber.php
index da58151..ad7317d 100644
--- a/src/Netzmacht/Contao/Leaflet/Subscriber/BootSubscriber.php
+++ b/src/Netzmacht/Contao/Leaflet/Subscriber/BootSubscriber.php
@@ -131,31 +131,34 @@ class BootSubscriber implements EventSubscriberInterface
 
         if ($collection) {
             /** @var DefinitionMapper $mapper */
-            $buffer  = '';
-            $mapper  = $GLOBALS['container']['leaflet.definition.mapper'];
+            $mapper = $GLOBALS['container']['leaflet.definition.mapper'];
+            $buffer = '';
+            $icons  = array();
+
             /** @var Leaflet $builder */
             $builder = $GLOBALS['container']['leaflet.definition.builder'];
             $encoder = $builder->getBuilder()->getEncoder();
 
             foreach ($collection as $model) {
                 /** @var Icon $icon */
-                $icon = $mapper->handle($model);
-
-                $buffer .= sprintf(
-                    'ContaoLeaflet.addIcon(\'%s\', L.icon(%s));' . "\n",
-                    $model->alias ?: ('icon_' . $model->id),
-                    $encoder->encodeValue($icon->getOptions())
+                $icon    = $mapper->handle($model);
+                $icons[] = array(
+                    'id'      => $icon->getId(),
+                    'type'    => lcfirst($icon->getType()),
+                    'options' => $icon->getOptions(),
                 );
             }
 
-            if ($buffer) {
-                $file = new \File('assets/leaflet/js/icons.js');
-                $file->write($buffer);
-                $file->close();
-
-                // TODO: Cache it.
-                $GLOBALS['TL_JAVASCRIPT'][] = 'assets/leaflet/js/icons.js|static';
+            if ($icons) {
+                $buffer = sprintf('ContaoLeaflet.loadIcons(%s);', $encoder->encodeValue($icons));
             }
+
+            $file = new \File('assets/leaflet/js/icons.js');
+            $file->write($buffer);
+            $file->close();
+
+            // TODO: Cache it.
+            $GLOBALS['TL_JAVASCRIPT'][] = 'assets/leaflet/js/icons.js|static';
         }
     }
 }