diff --git a/src/Api/Customer.php b/src/Api/Customer.php
index 3b7993c..3acd0db 100644
--- a/src/Api/Customer.php
+++ b/src/Api/Customer.php
@@ -85,7 +85,7 @@ public function create(Model $customer)
 
     /**
      * @param int   $customerNo
-     * @param Model $costumer
+     * @param Model $customer
      *
      * @return Model|ResponseInterface
      *
@@ -94,9 +94,9 @@ public function create(Model $customer)
      *
      * @see https://billogram.com/api/documentation#customers_edit
      */
-    public function update(int $customerNo, Model $costumer)
+    public function update(int $customerNo, Model $customer)
     {
-        $response = $this->httpPut('/customer/'.$customerNo, $costumer->toArray());
+        $response = $this->httpPut('/customer/'.$customerNo, $customer->toArray());
         if (!$this->hydrator) {
             return $response;
         }
diff --git a/tests/Api/CostumerTest.php b/tests/Api/CustomerTest.php
similarity index 99%
rename from tests/Api/CostumerTest.php
rename to tests/Api/CustomerTest.php
index 3831a6a..5950945 100644
--- a/tests/Api/CostumerTest.php
+++ b/tests/Api/CustomerTest.php
@@ -17,7 +17,7 @@
 /**
  * @author Ibrahim Hizeoui <ibrahimhizeoui@gmail.com>
  */
-class CostumerTest /*extends BaseTestCase*/
+class CustomerTest /*extends BaseTestCase*/
 {
     /*
      * @return string|null the directory where cached responses are stored