diff --git a/Mapzen.php b/Mapzen.php
index f7f561d..66b9ec9 100644
--- a/Mapzen.php
+++ b/Mapzen.php
@@ -180,7 +180,7 @@ private function executeQuery(string $url): AddressCollection
     /**
      * @param array $components
      *
-     * @return null|string
+     * @return string|null
      */
     protected function guessLocality(array $components)
     {
@@ -192,7 +192,7 @@ protected function guessLocality(array $components)
     /**
      * @param array $components
      *
-     * @return null|string
+     * @return string|null
      */
     protected function guessStreetName(array $components)
     {
@@ -204,7 +204,7 @@ protected function guessStreetName(array $components)
     /**
      * @param array $components
      *
-     * @return null|string
+     * @return string|null
      */
     protected function guessSubLocality(array $components)
     {
@@ -217,7 +217,7 @@ protected function guessSubLocality(array $components)
      * @param array $components
      * @param array $keys
      *
-     * @return null|string
+     * @return string|null
      */
     protected function guessBestComponent(array $components, array $keys)
     {