diff --git a/Mapbox.php b/Mapbox.php
index 97cf64f..be33073 100644
--- a/Mapbox.php
+++ b/Mapbox.php
@@ -148,7 +148,7 @@ final class Mapbox extends AbstractHttpProvider implements Provider
     public function __construct(
         ClientInterface $client,
         string $accessToken,
-        string $country = null,
+        ?string $country = null,
         string $geocodingMode = self::GEOCODING_MODE_PLACES
     ) {
         parent::__construct($client);
@@ -232,7 +232,7 @@ public function getName(): string
     /**
      * @return string query with extra params
      */
-    private function buildQuery(string $url, int $limit, string $locale = null, string $country = null): string
+    private function buildQuery(string $url, int $limit, ?string $locale = null, ?string $country = null): string
     {
         $parameters = array_filter([
             'country' => $country,
@@ -246,7 +246,7 @@ private function buildQuery(string $url, int $limit, string $locale = null, stri
         return $url.$separator.http_build_query($parameters);
     }
 
-    private function fetchUrl(string $url, int $limit, string $locale = null, string $country = null): AddressCollection
+    private function fetchUrl(string $url, int $limit, ?string $locale = null, ?string $country = null): AddressCollection
     {
         $url = $this->buildQuery($url, $limit, $locale, $country);
         $content = $this->getUrlContents($url);
diff --git a/Model/MapboxAddress.php b/Model/MapboxAddress.php
index 676d1a7..b767f32 100644
--- a/Model/MapboxAddress.php
+++ b/Model/MapboxAddress.php
@@ -46,7 +46,7 @@ final class MapboxAddress extends Address
      */
     private $neighborhood;
 
-    public function withId(string $id = null): self
+    public function withId(?string $id = null): self
     {
         $new = clone $this;
         $new->id = $id;
@@ -67,7 +67,7 @@ public function getStreetName(): ?string
         return $this->streetName;
     }
 
-    public function withStreetName(string $streetName = null): self
+    public function withStreetName(?string $streetName = null): self
     {
         $new = clone $this;
         $new->streetName = $streetName;
@@ -80,7 +80,7 @@ public function getStreetNumber(): ?string
         return $this->streetNumber;
     }
 
-    public function withStreetNumber(string $streetNumber = null): self
+    public function withStreetNumber(?string $streetNumber = null): self
     {
         $new = clone $this;
         $new->streetNumber = $streetNumber;
@@ -112,7 +112,7 @@ public function getFormattedAddress(): ?string
         return $this->formattedAddress;
     }
 
-    public function withFormattedAddress(string $formattedAddress = null): self
+    public function withFormattedAddress(?string $formattedAddress = null): self
     {
         $new = clone $this;
         $new->formattedAddress = $formattedAddress;
@@ -125,7 +125,7 @@ public function getNeighborhood(): ?string
         return $this->neighborhood;
     }
 
-    public function withNeighborhood(string $neighborhood = null): self
+    public function withNeighborhood(?string $neighborhood = null): self
     {
         $new = clone $this;
         $new->neighborhood = $neighborhood;