diff --git a/src/Models/Contacts/ContactIdentifier.php b/src/Models/Contacts/ContactIdentifier.php
index 799b2d5..f6a128c 100644
--- a/src/Models/Contacts/ContactIdentifier.php
+++ b/src/Models/Contacts/ContactIdentifier.php
@@ -100,7 +100,7 @@ public static function link(array $params): ContactIdentifier
     }
 
     /**
-     * @param array $params
+     * @param array<string, string> $params
      * @return ContactIdentifier
      * @throws MaintenanceModeException|GuzzleException|PiggyRequestException|PiggyRequestException
      */
@@ -113,7 +113,7 @@ public static function unlink(array $params): ContactIdentifier
     }
 
     /**
-     * @param array $params
+     * @param array<string, string> $params
      * @return ContactIdentifier
      * @throws MaintenanceModeException|GuzzleException|PiggyRequestException|PiggyRequestException
      */
diff --git a/src/Resources/OAuth/Contacts/ContactIdentifiersResource.php b/src/Resources/OAuth/Contacts/ContactIdentifiersResource.php
index 5cc0a81..b5fde65 100644
--- a/src/Resources/OAuth/Contacts/ContactIdentifiersResource.php
+++ b/src/Resources/OAuth/Contacts/ContactIdentifiersResource.php
@@ -63,6 +63,11 @@ public function link(string $contactIdentifierValue, string $contactUuid): Conta
         return $mapper->map($response->getData());
     }
 
+    /**
+     * @param string $contactIdentifierValue
+     * @return ContactIdentifier
+     * @throws PiggyRequestException
+     */
     public function unlink(string $contactIdentifierValue): ContactIdentifier
     {
         $response = $this->client->put("$this->resourceUri/unlink", [
@@ -75,7 +80,8 @@ public function unlink(string $contactIdentifierValue): ContactIdentifier
     }
 
     /**
-     * @return null
+     * @param string $contactIdentifierValue
+     * @return mixed|mixed[]|\stdClass
      * @throws PiggyRequestException
      */
     public function delete(string $contactIdentifierValue)