diff --git a/src/EventSubscriber/LocaleRewriteSubscriber.php b/src/EventSubscriber/LocaleRewriteSubscriber.php
index 8001e24..477bda6 100644
--- a/src/EventSubscriber/LocaleRewriteSubscriber.php
+++ b/src/EventSubscriber/LocaleRewriteSubscriber.php
@@ -68,7 +68,7 @@ private function getPreferredLanguage(Request $request): ?string
 
     private function routeExists(string $path): bool
     {
-        return !empty(array_filter((array)$this->routeCollection->getIterator(), function($routeObject) use ($path) {
+        return !empty(array_filter(iterator_to_array($this->routeCollection->getIterator()), function($routeObject) use ($path) {
             return $routeObject->getPath() === "/{" . $this->localeRouteParam . "}" . $path;
         }));
     }
diff --git a/tests/Functional/DefaultTest.php b/tests/Functional/DefaultTest.php
index 748f00a..5cbd453 100644
--- a/tests/Functional/DefaultTest.php
+++ b/tests/Functional/DefaultTest.php
@@ -4,6 +4,7 @@
 use Braunstetter\LocalizedRoutes\Tests\Functional\app\src\TestKernel;
 use PHPUnit\Framework\TestCase;
 use Symfony\Bundle\FrameworkBundle\KernelBrowser;
+use Symfony\Component\HttpFoundation\AcceptHeader;
 
 class DefaultTest extends TestCase
 {
@@ -28,7 +29,7 @@ public function test_route_gets_redirected()
         $this->assertSame('http://localhost/en/test', $client->getRequest()->getUri());
     }
 
-    public function test_route_gets_redirected_even_with_unsupported_locale()
+    public function test_route_gets_redirected_to_default_locale_when_locale_is_unsupported()
     {
         $kernel = new TestKernel(['/Resources/config/parameters-unsupported-locale.yaml']);
         $kernel->reboot($kernel->getCacheDir() . '/warmup');
@@ -36,9 +37,8 @@ public function test_route_gets_redirected_even_with_unsupported_locale()
         $client = new KernelBrowser($kernel);
         $client->followRedirects();
         $client->request('GET', '/test-unsupported');
-        $this->assertSame('http://localhost/en/test-unsupported', $client->getRequest()->getUri());
-        $this->assertFalse($client->getResponse()->isSuccessful());
-        $this->assertSame(404, $client->getResponse()->getStatusCode());
+        $this->assertSame('http://localhost/es/test-unsupported', $client->getRequest()->getUri());
+        $this->assertTrue($client->getResponse()->isSuccessful());
     }
 
     public function test_home_fallback_works() {
diff --git a/tests/Functional/app/src/Resources/config/framework.yaml b/tests/Functional/app/src/Resources/config/framework.yaml
index 4498d02..73645c2 100644
--- a/tests/Functional/app/src/Resources/config/framework.yaml
+++ b/tests/Functional/app/src/Resources/config/framework.yaml
@@ -1,6 +1,6 @@
 framework:
   secret: 'F00'
-  default_locale: 'en'
+  default_locale: es
   router:
     utf8: true
     resource: '%kernel.project_dir%/tests/Functional/app/src/Resources/config/routes.yaml'
diff --git a/tests/Functional/app/src/Resources/config/parameters-unsupported-locale.yaml b/tests/Functional/app/src/Resources/config/parameters-unsupported-locale.yaml
index be1d7c4..0e6633f 100644
--- a/tests/Functional/app/src/Resources/config/parameters-unsupported-locale.yaml
+++ b/tests/Functional/app/src/Resources/config/parameters-unsupported-locale.yaml
@@ -1,3 +1,3 @@
 parameters:
   app_locales: fr|es
-  locale: en
\ No newline at end of file
+  locale: es
\ No newline at end of file
diff --git a/tests/Unit/UnitTest.php b/tests/Unit/UnitTest.php
new file mode 100644
index 0000000..7c8be14
--- /dev/null
+++ b/tests/Unit/UnitTest.php
@@ -0,0 +1,43 @@
+<?php
+
+use Braunstetter\LocalizedRoutes\EventSubscriber\LocaleRewriteSubscriber;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
+use Symfony\Component\Routing\RouteCollection;
+use Symfony\Component\Routing\RouterInterface;
+
+class UnitTest extends TestCase
+{
+
+    /**
+     * @throws ReflectionException
+     */
+    public function test_is_locale_supported()
+    {
+        $routerMock = $this->getMockBuilder(RouterInterface::class)->getMock();
+        $routerMock->method('getRouteCollection')->willReturn(new RouteCollection());
+        $parameterBagMock = $this->getMockBuilder(ParameterBagInterface::class)->getMock();
+        $subscriber = new LocaleRewriteSubscriber($routerMock, $parameterBagMock);
+
+        $this->assertFalse($this->invokeMethod($subscriber, 'isLocaleSupported', [null]));
+    }
+
+    /**
+     * Call protected/private method of a class.
+     *
+     * @param object &$object Instantiated object that we will run method on.
+     * @param string $methodName Method names to call
+     * @param array $parameters Array of parameters to pass into method.
+     *
+     * @return mixed Method return.
+     * @throws ReflectionException
+     */
+    public function invokeMethod(object $object, string $methodName, array $parameters = array()): mixed
+    {
+        $reflection = new \ReflectionClass(get_class($object));
+        $method = $reflection->getMethod($methodName);
+        $method->setAccessible(true);
+
+        return $method->invokeArgs($object, $parameters);
+    }
+}
\ No newline at end of file
diff --git a/tests/coverage.xml b/tests/coverage.xml
index f8a2575..bb28f89 100644
--- a/tests/coverage.xml
+++ b/tests/coverage.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<coverage generated="1652730267">
-  <project timestamp="1652730267">
+<coverage generated="1652799211">
+  <project timestamp="1652799211">
     <file name="/Users/michaelbrauner/Bundles/Symfony/LocalizedRoutesBundle/src/DependencyInjection/LocalizedRoutesExtension.php">
       <class name="Braunstetter\LocalizedRoutes\DependencyInjection\LocalizedRoutesExtension" namespace="global">
         <metrics complexity="1" methods="1" coveredmethods="1" conditionals="0" coveredconditionals="0" statements="2" coveredstatements="2" elements="3" coveredelements="3"/>
@@ -12,12 +12,12 @@
     </file>
     <file name="/Users/michaelbrauner/Bundles/Symfony/LocalizedRoutesBundle/src/EventSubscriber/LocaleRewriteSubscriber.php">
       <class name="Braunstetter\LocalizedRoutes\EventSubscriber\LocaleRewriteSubscriber" namespace="global">
-        <metrics complexity="11" methods="6" coveredmethods="5" conditionals="0" coveredconditionals="0" statements="20" coveredstatements="19" elements="26" coveredelements="24"/>
+        <metrics complexity="11" methods="6" coveredmethods="6" conditionals="0" coveredconditionals="0" statements="20" coveredstatements="20" elements="26" coveredelements="26"/>
       </class>
-      <line num="23" type="method" name="__construct" visibility="public" complexity="1" crap="1" count="3"/>
-      <line num="25" type="stmt" count="3"/>
-      <line num="26" type="stmt" count="3"/>
-      <line num="27" type="stmt" count="3"/>
+      <line num="23" type="method" name="__construct" visibility="public" complexity="1" crap="1" count="4"/>
+      <line num="25" type="stmt" count="4"/>
+      <line num="26" type="stmt" count="4"/>
+      <line num="27" type="stmt" count="4"/>
       <line num="30" type="method" name="onKernelRequest" visibility="public" complexity="3" crap="3" count="3"/>
       <line num="32" type="stmt" count="3"/>
       <line num="33" type="stmt" count="3"/>
@@ -27,9 +27,9 @@
       <line num="42" type="stmt" count="2"/>
       <line num="43" type="stmt" count="1"/>
       <line num="46" type="stmt" count="2"/>
-      <line num="51" type="method" name="isLocaleSupported" visibility="private" complexity="3" crap="3.07" count="2"/>
-      <line num="53" type="stmt" count="2"/>
-      <line num="54" type="stmt" count="0"/>
+      <line num="51" type="method" name="isLocaleSupported" visibility="private" complexity="3" crap="3" count="3"/>
+      <line num="53" type="stmt" count="3"/>
+      <line num="54" type="stmt" count="1"/>
       <line num="57" type="stmt" count="2"/>
       <line num="58" type="stmt" count="2"/>
       <line num="61" type="stmt" count="2"/>
@@ -40,7 +40,7 @@
       <line num="72" type="stmt" count="3"/>
       <line num="76" type="method" name="getSubscribedEvents" visibility="public" complexity="1" crap="1" count="2"/>
       <line num="79" type="stmt" count="2"/>
-      <metrics loc="83" ncloc="81" classes="1" methods="6" coveredmethods="5" conditionals="0" coveredconditionals="0" statements="20" coveredstatements="19" elements="26" coveredelements="24"/>
+      <metrics loc="83" ncloc="81" classes="1" methods="6" coveredmethods="6" conditionals="0" coveredconditionals="0" statements="20" coveredstatements="20" elements="26" coveredelements="26"/>
     </file>
     <file name="/Users/michaelbrauner/Bundles/Symfony/LocalizedRoutesBundle/src/LocalizedRoutesBundle.php">
       <class name="Braunstetter\LocalizedRoutes\LocalizedRoutesBundle" namespace="global">
@@ -50,6 +50,6 @@
       <line num="12" type="stmt" count="1"/>
       <metrics loc="14" ncloc="14" classes="1" methods="1" coveredmethods="1" conditionals="0" coveredconditionals="0" statements="1" coveredstatements="1" elements="2" coveredelements="2"/>
     </file>
-    <metrics files="3" loc="117" ncloc="111" classes="3" methods="8" coveredmethods="7" conditionals="0" coveredconditionals="0" statements="23" coveredstatements="22" elements="31" coveredelements="29"/>
+    <metrics files="3" loc="117" ncloc="111" classes="3" methods="8" coveredmethods="8" conditionals="0" coveredconditionals="0" statements="23" coveredstatements="23" elements="31" coveredelements="31"/>
   </project>
 </coverage>