diff --git a/src/Pecee/Http/Input/InputHandler.php b/src/Pecee/Http/Input/InputHandler.php
index e485505..c6a000d 100644
--- a/src/Pecee/Http/Input/InputHandler.php
+++ b/src/Pecee/Http/Input/InputHandler.php
@@ -319,7 +319,7 @@ class InputHandler
     public function all(array $filter = []): array
     {
         $output = $this->originalParams + $this->originalPost + $this->originalFile;
-        $output = (\count($filter) > 0) ? array_intersect_key($output, array_flip($filter)) : $output;
+        $output = (\count($filter) > 0) ? \array_intersect_key($output, \array_flip($filter)) : $output;
 
         foreach ($filter as $filterKey) {
             if (array_key_exists($filterKey, $output) === false) {
diff --git a/src/Pecee/SimpleRouter/ClassLoader/ClassLoader.php b/src/Pecee/SimpleRouter/ClassLoader/ClassLoader.php
index 8c431a2..f1e5729 100644
--- a/src/Pecee/SimpleRouter/ClassLoader/ClassLoader.php
+++ b/src/Pecee/SimpleRouter/ClassLoader/ClassLoader.php
@@ -2,7 +2,7 @@
 
 namespace Pecee\SimpleRouter\ClassLoader;
 
-use Pecee\SimpleRouter\Exceptions\NotFoundHttpException;
+use Pecee\SimpleRouter\Exceptions\ClassNotFoundHttpException;
 
 class ClassLoader implements IClassLoader
 {
@@ -15,8 +15,8 @@ class ClassLoader implements IClassLoader
      */
     public function loadClass(string $class)
     {
-        if (\class_exists($class) === false) {
-            throw new NotFoundHttpException(sprintf('Class "%s" does not exist', $class), 404);
+        if (class_exists($class) === false) {
+            throw new ClassNotFoundHttpException(sprintf('Class "%s" does not exist', $class), 404, null, $class);
         }
 
         return new $class();
diff --git a/src/Pecee/SimpleRouter/Exceptions/ClassNotFoundHttpException.php b/src/Pecee/SimpleRouter/Exceptions/ClassNotFoundHttpException.php
new file mode 100644
index 0000000..d283874
--- /dev/null
+++ b/src/Pecee/SimpleRouter/Exceptions/ClassNotFoundHttpException.php
@@ -0,0 +1,38 @@
+<?php
+
+namespace Pecee\SimpleRouter\Exceptions;
+
+use Throwable;
+
+class ClassNotFoundHttpException extends NotFoundHttpException
+{
+    protected $class;
+    protected $method;
+
+    public function __construct($message = "", $code = 0, Throwable $previous = null, string $class, ?string $method = null)
+    {
+        parent::__construct($message, $code, $previous);
+
+        $this->class = $class;
+        $this->method = $method;
+    }
+
+    /**
+     * Get class name
+     * @return string
+     */
+    public function getClass(): string
+    {
+        return $this->class;
+    }
+
+    /**
+     * Get method
+     * @return string|null
+     */
+    public function getMethod(): ?string
+    {
+        return $this->method;
+    }
+
+}
\ No newline at end of file
diff --git a/src/Pecee/SimpleRouter/Route/Route.php b/src/Pecee/SimpleRouter/Route/Route.php
index 8dc45bf..1696c98 100644
--- a/src/Pecee/SimpleRouter/Route/Route.php
+++ b/src/Pecee/SimpleRouter/Route/Route.php
@@ -4,6 +4,7 @@ namespace Pecee\SimpleRouter\Route;
 
 use Pecee\Http\Middleware\IMiddleware;
 use Pecee\Http\Request;
+use Pecee\SimpleRouter\Exceptions\ClassNotFoundHttpException;
 use Pecee\SimpleRouter\Exceptions\NotFoundHttpException;
 use Pecee\SimpleRouter\Router;
 
@@ -94,7 +95,7 @@ abstract class Route implements IRoute
         }
 
         if (method_exists($class, $method) === false) {
-            throw new NotFoundHttpException(sprintf('Method "%s" does not exist in class "%s"', $method, $className), 404);
+            throw new ClassNotFoundHttpException(sprintf('Method "%s" does not exist in class "%s"', $method, $className), 404, null, $className, $method);
         }
 
         $router->debug('Executing callback');
diff --git a/src/Pecee/SimpleRouter/SimpleRouter.php b/src/Pecee/SimpleRouter/SimpleRouter.php
index ffea26a..5711303 100644
--- a/src/Pecee/SimpleRouter/SimpleRouter.php
+++ b/src/Pecee/SimpleRouter/SimpleRouter.php
@@ -58,6 +58,11 @@ class SimpleRouter
      */
     public static function start(): void
     {
+        // Set default namespaces
+        foreach (static::router()->getRoutes() as $route) {
+            static::addDefaultNamespace($route);
+        }
+
         echo static::router()->start();
     }
 
@@ -306,8 +311,8 @@ class SimpleRouter
      * @param string $url
      * @param string|array|\Closure $callback
      * @param array|null $settings
-     * @see SimpleRouter::form
      * @return RouteUrl
+     * @see SimpleRouter::form
      */
     public static function basic(string $url, $callback, array $settings = null): IRoute
     {
@@ -321,14 +326,14 @@ class SimpleRouter
      * @param string $url
      * @param string|array|\Closure $callback
      * @param array|null $settings
-     * @see SimpleRouter::form
      * @return RouteUrl
+     * @see SimpleRouter::form
      */
     public static function form(string $url, $callback, array $settings = null): IRoute
     {
         return static::match([
             Request::REQUEST_TYPE_GET,
-            Request::REQUEST_TYPE_POST
+            Request::REQUEST_TYPE_POST,
         ], $url, $callback, $settings);
     }
 
@@ -345,7 +350,6 @@ class SimpleRouter
     {
         $route = new RouteUrl($url, $callback);
         $route->setRequestMethods($requestMethods);
-        $route = static::addDefaultNamespace($route);
 
         if ($settings !== null) {
             $route->setSettings($settings);
@@ -365,7 +369,6 @@ class SimpleRouter
     public static function all(string $url, $callback, array $settings = null)
     {
         $route = new RouteUrl($url, $callback);
-        $route = static::addDefaultNamespace($route);
 
         if ($settings !== null) {
             $route->setSettings($settings);
@@ -385,7 +388,6 @@ class SimpleRouter
     public static function controller(string $url, string $controller, array $settings = null)
     {
         $route = new RouteController($url, $controller);
-        $route = static::addDefaultNamespace($route);
 
         if ($settings !== null) {
             $route->setSettings($settings);
@@ -405,7 +407,6 @@ class SimpleRouter
     public static function resource(string $url, string $controller, array $settings = null)
     {
         $route = new RouteResource($url, $controller);
-        $route = static::addDefaultNamespace($route);
 
         if ($settings !== null) {
             $route->setSettings($settings);
@@ -510,22 +511,19 @@ class SimpleRouter
     {
         if (static::$defaultNamespace !== null) {
 
-            $callback = $route->getCallback();
+            $ns = static::$defaultNamespace;
+            $namespace = $route->getNamespace();
 
-            /* Only add default namespace on relative callbacks */
-            if ($callback === null || (\is_string($callback) === true && $callback[0] !== '\\')) {
-
-                $namespace = static::$defaultNamespace;
-
-                $currentNamespace = $route->getNamespace();
-
-                if ($currentNamespace !== null) {
-                    $namespace .= '\\' . $currentNamespace;
+            if ($namespace !== null) {
+                // Don't overwrite namespaces that starts with \
+                if ($namespace[0] !== '\\') {
+                    $ns .= '\\' . $namespace;
+                } else {
+                    $ns = $namespace;
                 }
-
-                $route->setDefaultNamespace($namespace);
-
             }
+
+            $route->setNamespace($ns);
         }
 
         return $route;
diff --git a/tests/Pecee/SimpleRouter/RouterUrlTest.php b/tests/Pecee/SimpleRouter/RouterUrlTest.php
index 2aa4706..b360973 100644
--- a/tests/Pecee/SimpleRouter/RouterUrlTest.php
+++ b/tests/Pecee/SimpleRouter/RouterUrlTest.php
@@ -11,7 +11,7 @@ class RouterUrlTest extends \PHPUnit\Framework\TestCase
     {
         TestRouter::get('/', 'DummyController@method1');
         TestRouter::get('/page/{id?}', 'DummyController@method1');
-        TestRouter::get('/test-output', function() {
+        TestRouter::get('/test-output', function () {
             return 'return value';
         });
 
@@ -175,7 +175,7 @@ class RouterUrlTest extends \PHPUnit\Framework\TestCase
     {
         TestRouter::request()->setHost('google.com');
 
-        TestRouter::get('/admin/', function() {
+        TestRouter::get('/admin/', function () {
             return 'match';
         })->setMatch('/^\/admin\/?(.*)/i');
 
@@ -183,4 +183,54 @@ class RouterUrlTest extends \PHPUnit\Framework\TestCase
         $this->assertEquals('match', $output);
     }
 
+    public function testDefaultNamespace()
+    {
+        TestRouter::setDefaultNamespace('\\Default\\Namespace');
+
+        TestRouter::get('/', 'DummyController@method1', ['as' => 'home']);
+
+        TestRouter::group([
+            'namespace' => 'Appended\Namespace',
+            'prefix'    => '/horses',
+        ], function () {
+
+            TestRouter::get('/', 'DummyController@method1');
+
+            TestRouter::group([
+                'namespace' => '\\New\\Namespace',
+                'prefix'    => '/race',
+            ], function () {
+
+                TestRouter::get('/', 'DummyController@method1');
+
+            });
+        });
+
+        // Test appended namespace
+
+        $class = null;
+
+        try {
+            TestRouter::debugNoReset('/horses/');
+        } catch (\Pecee\SimpleRouter\Exceptions\ClassNotFoundHttpException $e) {
+            $class = $e->getClass();
+        }
+
+        $this->assertEquals('\\Default\\Namespace\\Appended\Namespace\\DummyController', $class);
+
+        // Test overwritten namespace
+
+        $class = null;
+
+        try {
+            TestRouter::debugNoReset('/horses/race');
+        } catch (\Pecee\SimpleRouter\Exceptions\ClassNotFoundHttpException $e) {
+            $class = $e->getClass();
+        }
+
+        $this->assertEquals('\\New\\Namespace\\DummyController', $class);
+
+        TestRouter::router()->reset();
+    }
+
 }
\ No newline at end of file