diff --git a/lib/API/API.php b/lib/API/API.php
index 8566436109..d03247684e 100644
--- a/lib/API/API.php
+++ b/lib/API/API.php
@@ -25,7 +25,7 @@ class API {
   function __construct() {
     foreach($this->_available_api_versions as $available_api_version) {
       $this->addEndpointNamespace(
-        sprintf('%s\%s', __NAMESPACE__, self::ENDPOINTS_LOCATION),
+        sprintf('%s\%s\%s', __NAMESPACE__, self::ENDPOINTS_LOCATION, $available_api_version),
         $available_api_version
       );
     }
@@ -89,9 +89,8 @@ class API {
     } else if(!empty($this->_endpoint_namespaces[$this->_request_api_version])) {
       foreach($this->_endpoint_namespaces[$this->_request_api_version] as $namespace) {
         $endpoint_class = sprintf(
-          '%s\%s\%s',
+          '%s\%s',
           $namespace,
-          $this->_request_api_version,
           ucfirst($this->_request_endpoint)
         );
         if(class_exists($endpoint_class)) {
diff --git a/tests/unit/API/APITest.php b/tests/unit/API/APITest.php
index 9932feb6bb..81559d1956 100644
--- a/tests/unit/API/APITest.php
+++ b/tests/unit/API/APITest.php
@@ -84,7 +84,7 @@ class APITest extends MailPoetTest {
 
   function testItAcceptsAndProcessesAPIVersion() {
     $namespace = array(
-      'name' => 'MailPoet\API\Endpoints',
+      'name' => 'MailPoet\API\Endpoints\v2',
       'version' => 'v2'
     );
     $this->api->addEndpointNamespace($namespace['name'], $namespace['version']);
@@ -104,7 +104,7 @@ class APITest extends MailPoetTest {
 
   function testItCallsAddedEndpoints() {
     $namespace = array(
-      'name' => 'MailPoet\API\Endpoints',
+      'name' => 'MailPoet\API\Endpoints\v1',
       'version' => 'v1'
     );
     $this->api->addEndpointNamespace($namespace['name'], $namespace['version']);
@@ -123,7 +123,7 @@ class APITest extends MailPoetTest {
 
   function testItCallsAddedEndpointsForSpecificAPIVersion() {
     $namespace = array(
-      'name' => 'MailPoet\API\Endpoints',
+      'name' => 'MailPoet\API\Endpoints\v2',
       'version' => 'v2'
     );
     $this->api->addEndpointNamespace($namespace['name'], $namespace['version']);