diff --git a/src/Provider/Node/FallbackNodeProvider.php b/src/Provider/Node/FallbackNodeProvider.php
index e4e4504..97c1699 100644
--- a/src/Provider/Node/FallbackNodeProvider.php
+++ b/src/Provider/Node/FallbackNodeProvider.php
@@ -38,7 +38,7 @@ class FallbackNodeProvider implements NodeProviderInterface
     /**
      * @inheritDoc
      */
-    public function getNode()
+    public function getNode(): ?string
     {
         foreach ($this->nodeProviders as $provider) {
             if ($node = $provider->getNode()) {
diff --git a/src/Provider/Node/RandomNodeProvider.php b/src/Provider/Node/RandomNodeProvider.php
index 309f1fd..6b3035d 100644
--- a/src/Provider/Node/RandomNodeProvider.php
+++ b/src/Provider/Node/RandomNodeProvider.php
@@ -27,7 +27,7 @@ class RandomNodeProvider implements NodeProviderInterface
     /**
      * @inheritDoc
      */
-    public function getNode()
+    public function getNode(): string
     {
         try {
             $nodeBytes = random_bytes(6);
diff --git a/src/Uuid.php b/src/Uuid.php
index 1d11580..694c1c9 100644
--- a/src/Uuid.php
+++ b/src/Uuid.php
@@ -569,6 +569,9 @@ class Uuid implements UuidInterface
         return (int) hexdec($this->getTimestampHex());
     }
 
+    /**
+     * @inheritdoc
+     */
     public function getTimestampHex(): string
     {
         if ($this->getVersion() !== 1) {