diff --git a/src/Events/DefaultEventFactory.php b/src/Events/DefaultEventFactory.php
index 811aa3f..b7ca7b7 100644
--- a/src/Events/DefaultEventFactory.php
+++ b/src/Events/DefaultEventFactory.php
@@ -31,7 +31,7 @@ public function newSpan(string $name, EventBean $parent): Span
     /**
      * {@inheritdoc}
      */
-    public function newMetricset($set, $tags): Metricset
+    public function newMetricset(array $set, array $tags = []): Metricset
     {
         return new Metricset($set, $tags);
     }
diff --git a/src/Events/EventFactoryInterface.php b/src/Events/EventFactoryInterface.php
index d7db1cd..068f488 100644
--- a/src/Events/EventFactoryInterface.php
+++ b/src/Events/EventFactoryInterface.php
@@ -45,6 +45,6 @@ public function newSpan(string $name, EventBean $parent): Span;
      *
      * @return Metricset
      */
-    public function newMetricset($set, $tags): Metricset;
+    public function newMetricset(array $set, array $tags = []): Metricset;
 
 }
diff --git a/src/Events/Metricset.php b/src/Events/Metricset.php
index f64edf2..c839990 100644
--- a/src/Events/Metricset.php
+++ b/src/Events/Metricset.php
@@ -26,7 +26,7 @@ class Metricset extends EventBean implements \JsonSerializable
      * @param array $set
      * @param array $tags
      */
-    public function __construct(array $set, array $tags)
+    public function __construct(array $set, array $tags = [])
     {
         parent::__construct([]);
         foreach($set as $k => $v) {
@@ -47,6 +47,7 @@ public function jsonSerialize() : array
         return [
             'metricset' => [
                 'samples'   => $this->samples,
+//                'tags'      => $this->tags,
                 'timestamp' => $this->getTimestamp(),
             ]
         ];