diff --git a/composer.json b/composer.json
index 7b18724..43e4a5f 100644
--- a/composer.json
+++ b/composer.json
@@ -31,8 +31,12 @@
     "ext-json": "*"
   },
   "require-dev": {
-    "phpunit/phpunit": "^7",
-    "mockery/mockery": "^1"
+    "phpunit/phpunit": "^8",
+    "mockery/mockery": "^1",
+    "phpstan/phpstan": "^0",
+    "phpstan/phpstan-phpunit": "^0",
+    "phpstan/phpstan-deprecation-rules": "^0",
+    "phpstan/phpstan-strict-rules": "^0"
   },
   "scripts": {
     "test": [
@@ -44,4 +48,4 @@
       "Pecee\\": "src/Pecee/"
     }
   }
-}
+}
\ No newline at end of file
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..3719f4a
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,22 @@
+parameters:
+	level: 6
+	paths:
+		- src
+	fileExtensions:
+		- php
+	bootstrapFiles:
+	    - ./vendor/autoload.php
+	ignoreErrors:
+	reportUnmatchedIgnoredErrors: true
+	checkMissingIterableValueType: false
+	checkGenericClassInNonGenericObjectType: false
+	parallel:
+		processTimeout: 300.0
+		jobSize: 10
+		maximumNumberOfProcesses: 4
+		minimumNumberOfJobsPerProcess: 4
+includes:
+    - vendor/phpstan/phpstan-strict-rules/rules.neon
+    - vendor/phpstan/phpstan-phpunit/extension.neon
+    - vendor/phpstan/phpstan-phpunit/rules.neon
+    - vendor/phpstan/phpstan-deprecation-rules/rules.neon
\ No newline at end of file
diff --git a/src/Pecee/Http/Input/IInputItem.php b/src/Pecee/Http/Input/IInputItem.php
index 0c851c8..430b557 100644
--- a/src/Pecee/Http/Input/IInputItem.php
+++ b/src/Pecee/Http/Input/IInputItem.php
@@ -13,8 +13,14 @@ interface IInputItem
 
     public function setName(string $name): self;
 
+    /**
+     * @return mixed
+     */
     public function getValue();
 
+    /**
+     * @param mixed $value
+     */
     public function setValue($value): self;
 
     public function __toString(): string;
diff --git a/src/Pecee/Http/Input/InputHandler.php b/src/Pecee/Http/Input/InputHandler.php
index e909382..8cbfae7 100644
--- a/src/Pecee/Http/Input/InputHandler.php
+++ b/src/Pecee/Http/Input/InputHandler.php
@@ -115,7 +115,7 @@ class InputHandler
 
             // Handle array input
             if (is_array($value['name']) === false) {
-                $values['index'] = $parentKey ?? $key;
+                $values = ['index' => $parentKey ?? $key];
 
                 try {
                     $list[$key] = InputFile::createFromArray($values + $value);
@@ -161,7 +161,7 @@ class InputHandler
                 try {
 
                     $file = InputFile::createFromArray([
-                        'index'    => (empty($key) === true && empty($originalIndex) === false) ? $originalIndex : $key,
+                        'index'    => ($key === '' && $originalIndex !== '') ? $originalIndex : $key,
                         'name'     => $original['name'][$key],
                         'error'    => $original['error'][$key],
                         'tmp_name' => $original['tmp_name'][$key],
diff --git a/src/Pecee/Http/Request.php b/src/Pecee/Http/Request.php
index 4c5ee42..12ede38 100644
--- a/src/Pecee/Http/Request.php
+++ b/src/Pecee/Http/Request.php
@@ -137,7 +137,7 @@ class Request
 
     public function isSecure(): bool
     {
-        return $this->getHeader('http-x-forwarded-proto') === 'https' || $this->getHeader('https') !== null || $this->getHeader('server-port') === 443;
+        return $this->getHeader('http-x-forwarded-proto') === 'https' || $this->getHeader('https') !== null || (int)$this->getHeader('server-port') === 443;
     }
 
     /**
diff --git a/src/Pecee/Http/Url.php b/src/Pecee/Http/Url.php
index d856a54..3df21e2 100644
--- a/src/Pecee/Http/Url.php
+++ b/src/Pecee/Http/Url.php
@@ -387,7 +387,7 @@ class Url implements JsonSerializable
     {
         $encodedUrl = preg_replace_callback(
             '/[^:\/@?&=#]+/u',
-            static function ($matches) {
+            static function ($matches): string {
                 return urlencode($matches[0]);
             },
             $url
@@ -414,7 +414,7 @@ class Url implements JsonSerializable
         if (count($getParams) !== 0) {
 
             if ($includeEmpty === false) {
-                $getParams = array_filter($getParams, static function ($item) {
+                $getParams = array_filter($getParams, static function ($item): bool {
                     return (trim($item) !== '');
                 });
             }
@@ -458,7 +458,7 @@ class Url implements JsonSerializable
         $port = $this->port !== null ? ':' . $this->port : '';
         $user = $this->username ?? '';
         $pass = $this->password !== null ? ':' . $this->password : '';
-        $pass = ($user || $pass) ? $pass . '@' : '';
+        $pass = ($user !== '' || $pass !== '') ? $pass . '@' : '';
 
         return $scheme . $user . $pass . $host . $port . $this->getRelativeUrl($includeParams);
     }
@@ -466,7 +466,7 @@ class Url implements JsonSerializable
     /**
      * Specify data which should be serialized to JSON
      * @link http://php.net/manual/en/jsonserializable.jsonserialize.php
-     * @return mixed data which can be serialized by <b>json_encode</b>,
+     * @return string data which can be serialized by <b>json_encode</b>,
      * which is a value of any type other than a resource.
      * @since 5.4.0
      */
diff --git a/src/Pecee/SimpleRouter/Handlers/DebugEventHandler.php b/src/Pecee/SimpleRouter/Handlers/DebugEventHandler.php
index 92ff158..37eae16 100644
--- a/src/Pecee/SimpleRouter/Handlers/DebugEventHandler.php
+++ b/src/Pecee/SimpleRouter/Handlers/DebugEventHandler.php
@@ -17,7 +17,7 @@ class DebugEventHandler implements IEventHandler
 
     public function __construct()
     {
-        $this->callback = static function (EventArgument $argument) {
+        $this->callback = static function (EventArgument $argument): void {
             // todo: log in database
         };
     }
diff --git a/src/Pecee/SimpleRouter/Route/IControllerRoute.php b/src/Pecee/SimpleRouter/Route/IControllerRoute.php
index f5c879b..35e065e 100644
--- a/src/Pecee/SimpleRouter/Route/IControllerRoute.php
+++ b/src/Pecee/SimpleRouter/Route/IControllerRoute.php
@@ -2,7 +2,7 @@
 
 namespace Pecee\SimpleRouter\Route;
 
-interface IControllerRoute extends IRoute
+interface IControllerRoute extends ILoadableRoute
 {
     /**
      * Get controller class-name
diff --git a/src/Pecee/SimpleRouter/Route/Route.php b/src/Pecee/SimpleRouter/Route/Route.php
index 62da265..0932f31 100644
--- a/src/Pecee/SimpleRouter/Route/Route.php
+++ b/src/Pecee/SimpleRouter/Route/Route.php
@@ -67,7 +67,7 @@ abstract class Route implements IRoute
 
         /* Filter parameters with null-value */
         if ($this->filterEmptyParams === true) {
-            $parameters = array_filter($parameters, static function ($var) {
+            $parameters = array_filter($parameters, static function ($var): bool {
                 return ($var !== null);
             });
         }
@@ -82,6 +82,7 @@ abstract class Route implements IRoute
             }
 
             /* When the callback is a function */
+
             return $router->getClassLoader()->loadClosure($callback, $parameters);
         }
 
@@ -280,7 +281,7 @@ abstract class Route implements IRoute
     }
 
     /**
-     * @return string|callable
+     * @return string|callable|null
      */
     public function getCallback()
     {
@@ -337,6 +338,11 @@ abstract class Route implements IRoute
      */
     public function setNamespace(string $namespace): IRoute
     {
+        // Do not set namespace when class-hinting is used
+        if (is_array($this->callback) === true) {
+            return $this;
+        }
+
         $ns = $this->getNamespace();
 
         if ($ns !== null) {
diff --git a/src/Pecee/SimpleRouter/Route/RouteController.php b/src/Pecee/SimpleRouter/Route/RouteController.php
index 6c269b7..88c6597 100644
--- a/src/Pecee/SimpleRouter/Route/RouteController.php
+++ b/src/Pecee/SimpleRouter/Route/RouteController.php
@@ -52,7 +52,7 @@ class RouteController extends LoadableRoute implements IControllerRoute
     public function findUrl(?string $method = null, $parameters = null, ?string $name = null): string
     {
         if (strpos($name, '.') !== false) {
-            $found = array_search(substr($name, strrpos($name, '.') + 1), $this->names, false);
+            $found = array_search(substr($name, strrpos($name, '.') + 1), $this->names, true);
             if ($found !== false) {
                 $method = (string)$found;
             }
@@ -67,7 +67,7 @@ class RouteController extends LoadableRoute implements IControllerRoute
             foreach (Request::$requestTypes as $requestType) {
 
                 if (stripos($method, $requestType) === 0) {
-                    $method = (string)substr($method, strlen($requestType));
+                    $method = substr($method, strlen($requestType));
                     break;
                 }
             }
diff --git a/src/Pecee/SimpleRouter/Route/RouteResource.php b/src/Pecee/SimpleRouter/Route/RouteResource.php
index 5bbd41e..f8be0b7 100644
--- a/src/Pecee/SimpleRouter/Route/RouteResource.php
+++ b/src/Pecee/SimpleRouter/Route/RouteResource.php
@@ -54,7 +54,7 @@ class RouteResource extends LoadableRoute implements IControllerRoute
 
         /* Remove method/type */
         if (strpos($name, '.') !== false) {
-            $name = (string)substr($name, 0, strrpos($name, '.'));
+            $name = substr($name, 0, strrpos($name, '.'));
         }
 
         return (strtolower($this->name) === strtolower($name));
@@ -68,7 +68,7 @@ class RouteResource extends LoadableRoute implements IControllerRoute
      */
     public function findUrl(?string $method = null, $parameters = null, ?string $name = null): string
     {
-        $url = array_search($name, $this->names, false);
+        $url = array_search($name, $this->names, true);
         if ($url !== false) {
             return rtrim($this->url . $this->urls[$url], '/') . '/';
         }
diff --git a/src/Pecee/SimpleRouter/Router.php b/src/Pecee/SimpleRouter/Router.php
index 6225479..37b979a 100644
--- a/src/Pecee/SimpleRouter/Router.php
+++ b/src/Pecee/SimpleRouter/Router.php
@@ -44,7 +44,7 @@ class Router
 
     /**
      * List of processed routes
-     * @var array
+     * @var array|ILoadableRoute[]
      */
     protected $processedRoutes = [];
 
@@ -63,7 +63,7 @@ class Router
 
     /**
      * Csrf verifier class
-     * @var BaseCsrfVerifier
+     * @var BaseCsrfVerifier|null
      */
     protected $csrfVerifier;
 
@@ -107,7 +107,7 @@ class Router
 
     /**
      * Class loader instance
-     * @var ClassLoader
+     * @var IClassLoader
      */
     protected $classLoader;
 
@@ -215,7 +215,7 @@ class Router
         $exceptionHandlers = [];
 
         // Stop processing routes if no valid route is found.
-        if ($this->request->getRewriteRoute() === null && $this->request->getUrl() === null) {
+        if ($this->request->getRewriteRoute() === null && $this->request->getUrl()->getOriginalUrl() === '') {
             $this->debug('Halted route-processing as no valid route was found');
 
             return;
@@ -575,7 +575,6 @@ class Router
             'name' => $name,
         ]);
 
-        /* @var $route ILoadableRoute */
         foreach ($this->processedRoutes as $route) {
 
             /* Check if the name matches with a name on the route. Should match either router alias or controller alias. */
@@ -593,7 +592,7 @@ class Router
             }
 
             /* Using @ is most definitely a controller@method or alias@method */
-            if (is_string($name) === true && strpos($name, '@') !== false) {
+            if (strpos($name, '@') !== false) {
                 [$controller, $method] = array_map('strtolower', explode('@', $name));
 
                 if ($controller === strtolower($route->getClass()) && $method === strtolower($route->getMethod())) {
@@ -605,7 +604,7 @@ class Router
 
             /* Check if callback matches (if it's not a function) */
             $callback = $route->getCallback();
-            if (is_string($name) === true && is_string($callback) === true && is_callable($callback) === false && strpos($name, '@') !== false && strpos($callback, '@') !== false) {
+            if (is_string($callback) === true && is_callable($callback) === false && strpos($name, '@') !== false && strpos($callback, '@') !== false) {
 
                 /* Check if the entire callback is matching */
                 if (strpos($callback, $name) === 0 || strtolower($callback) === strtolower($name)) {
@@ -656,10 +655,6 @@ class Router
             'getParams'  => $getParams,
         ]);
 
-        if ($getParams !== null && is_array($getParams) === false) {
-            throw new InvalidArgumentException('Invalid type for getParams. Must be array or null');
-        }
-
         if ($name === '' && $parameters === '') {
             return new Url('/');
         }
@@ -703,21 +698,21 @@ class Router
             /* Loop through all the routes to see if we can find a match */
 
             /* @var $route ILoadableRoute */
-            foreach ($this->processedRoutes as $route) {
+            foreach ($this->processedRoutes as $processedRoute) {
 
                 /* Check if the route contains the name/alias */
-                if ($route->hasName($controller) === true) {
+                if ($processedRoute->hasName($controller) === true) {
                     return $this->request
                         ->getUrlCopy()
-                        ->setPath($route->findUrl($method, $parameters, $name))
+                        ->setPath($processedRoute->findUrl($method, $parameters, $name))
                         ->setParams($getParams);
                 }
 
                 /* Check if the route controller is equal to the name */
-                if ($route instanceof IControllerRoute && strtolower($route->getController()) === strtolower($controller)) {
+                if ($processedRoute instanceof IControllerRoute && strtolower($processedRoute->getController()) === strtolower($controller)) {
                     return $this->request
                         ->getUrlCopy()
-                        ->setPath($route->findUrl($method, $parameters, $name))
+                        ->setPath($processedRoute->findUrl($method, $parameters, $name))
                         ->setParams($getParams);
                 }
 
@@ -842,7 +837,7 @@ class Router
     /**
      * Get class loader
      *
-     * @return ClassLoader
+     * @return IClassLoader
      */
     public function getClassLoader(): IClassLoader
     {
diff --git a/src/Pecee/SimpleRouter/SimpleRouter.php b/src/Pecee/SimpleRouter/SimpleRouter.php
index 187a398..36aa73f 100644
--- a/src/Pecee/SimpleRouter/SimpleRouter.php
+++ b/src/Pecee/SimpleRouter/SimpleRouter.php
@@ -22,6 +22,7 @@ use Pecee\SimpleRouter\Exceptions\HttpException;
 use Pecee\SimpleRouter\Handlers\CallbackExceptionHandler;
 use Pecee\SimpleRouter\Handlers\IEventHandler;
 use Pecee\SimpleRouter\Route\IGroupRoute;
+use Pecee\SimpleRouter\Route\ILoadableRoute;
 use Pecee\SimpleRouter\Route\IPartialGroupRoute;
 use Pecee\SimpleRouter\Route\IRoute;
 use Pecee\SimpleRouter\Route\RouteController;
@@ -173,7 +174,7 @@ class SimpleRouter
      */
     public static function redirect(string $where, string $to, int $httpCode = 301): IRoute
     {
-        return static::get($where, function () use ($to, $httpCode) {
+        return static::get($where, static function () use ($to, $httpCode): void {
             static::response()->redirect($to, $httpCode);
         });
     }
@@ -185,7 +186,7 @@ class SimpleRouter
      * @param string|array|Closure $callback
      * @param array|null $settings
      *
-     * @return RouteUrl
+     * @return RouteUrl|IRoute
      */
     public static function get(string $url, $callback, array $settings = null): IRoute
     {
@@ -198,7 +199,7 @@ class SimpleRouter
      * @param string $url
      * @param string|array|Closure $callback
      * @param array|null $settings
-     * @return RouteUrl
+     * @return RouteUrl|IRoute
      */
     public static function post(string $url, $callback, array $settings = null): IRoute
     {
@@ -211,7 +212,7 @@ class SimpleRouter
      * @param string $url
      * @param string|array|Closure $callback
      * @param array|null $settings
-     * @return RouteUrl
+     * @return RouteUrl|IRoute
      */
     public static function put(string $url, $callback, array $settings = null): IRoute
     {
@@ -224,7 +225,7 @@ class SimpleRouter
      * @param string $url
      * @param string|array|Closure $callback
      * @param array|null $settings
-     * @return RouteUrl
+     * @return RouteUrl|IRoute
      */
     public static function patch(string $url, $callback, array $settings = null): IRoute
     {
@@ -237,7 +238,7 @@ class SimpleRouter
      * @param string $url
      * @param string|array|Closure $callback
      * @param array|null $settings
-     * @return RouteUrl
+     * @return RouteUrl|IRoute
      */
     public static function options(string $url, $callback, array $settings = null): IRoute
     {
@@ -250,7 +251,7 @@ class SimpleRouter
      * @param string $url
      * @param string|array|Closure $callback
      * @param array|null $settings
-     * @return RouteUrl
+     * @return RouteUrl|IRoute
      */
     public static function delete(string $url, $callback, array $settings = null): IRoute
     {
@@ -262,15 +263,11 @@ class SimpleRouter
      *
      * @param array $settings
      * @param Closure $callback
-     * @return RouteGroup
+     * @return RouteGroup|IGroupRoute
      * @throws InvalidArgumentException
      */
     public static function group(array $settings, Closure $callback): IGroupRoute
     {
-        if (is_callable($callback) === false) {
-            throw new InvalidArgumentException('Invalid callback provided. Only functions or methods supported');
-        }
-
         $group = new RouteGroup();
         $group->setCallback($callback);
         $group->setSettings($settings);
@@ -287,15 +284,11 @@ class SimpleRouter
      * @param string $url
      * @param Closure $callback
      * @param array $settings
-     * @return RoutePartialGroup
+     * @return RoutePartialGroup|IPartialGroupRoute
      * @throws InvalidArgumentException
      */
     public static function partialGroup(string $url, Closure $callback, array $settings = []): IPartialGroupRoute
     {
-        if (is_callable($callback) === false) {
-            throw new InvalidArgumentException('Invalid callback provided. Only functions or methods supported');
-        }
-
         $settings['prefix'] = $url;
 
         $group = new RoutePartialGroup();
@@ -313,7 +306,7 @@ class SimpleRouter
      * @param string $url
      * @param string|array|Closure $callback
      * @param array|null $settings
-     * @return RouteUrl
+     * @return RouteUrl|IRoute
      * @see SimpleRouter::form
      */
     public static function basic(string $url, $callback, array $settings = null): IRoute
@@ -328,7 +321,7 @@ class SimpleRouter
      * @param string $url
      * @param string|array|Closure $callback
      * @param array|null $settings
-     * @return RouteUrl
+     * @return RouteUrl|IRoute
      * @see SimpleRouter::form
      */
     public static function form(string $url, $callback, array $settings = null): IRoute
@@ -499,7 +492,7 @@ class SimpleRouter
     /**
      * Prepends the default namespace to all new routes added.
      *
-     * @param IRoute $route
+     * @param ILoadableRoute|IRoute $route
      * @return IRoute
      */
     public static function addDefaultNamespace(IRoute $route): IRoute
diff --git a/tests/Pecee/SimpleRouter/Dummy/NSController.php b/tests/Pecee/SimpleRouter/Dummy/NSController.php
new file mode 100644
index 0000000..fe8e33e
--- /dev/null
+++ b/tests/Pecee/SimpleRouter/Dummy/NSController.php
@@ -0,0 +1,11 @@
+<?php
+namespace MyNamespace;
+
+class NSController {
+
+    public function method()
+    {
+        return true;
+    }
+
+}
\ No newline at end of file
diff --git a/tests/Pecee/SimpleRouter/RouterRouteTest.php b/tests/Pecee/SimpleRouter/RouterRouteTest.php
index 3a3d2c1..971676a 100644
--- a/tests/Pecee/SimpleRouter/RouterRouteTest.php
+++ b/tests/Pecee/SimpleRouter/RouterRouteTest.php
@@ -2,6 +2,7 @@
 
 require_once 'Dummy/DummyMiddleware.php';
 require_once 'Dummy/DummyController.php';
+require_once 'Dummy/NSController.php';
 require_once 'Dummy/Exception/ExceptionHandlerException.php';
 
 class RouterRouteTest extends \PHPUnit\Framework\TestCase
@@ -246,6 +247,16 @@ class RouterRouteTest extends \PHPUnit\Framework\TestCase
         $this->assertTrue(true);
     }
 
+    public function testDefaultNameSpaceOverload()
+    {
+        TestRouter::setDefaultNamespace('DefaultNamespace\\Controllers');
+        TestRouter::get('/test', [\MyNamespace\NSController::class, 'method']);
+
+        $result = TestRouter::debugOutput('/test');
+
+        $this->assertTrue( (bool)$result);
+    }
+
     public function testSameRoutes()
     {
         TestRouter::get('/recipe', 'DummyController@method1')->name('add');
diff --git a/tests/TestRouter.php b/tests/TestRouter.php
index 1a1b4c1..79509df 100644
--- a/tests/TestRouter.php
+++ b/tests/TestRouter.php
@@ -22,12 +22,14 @@ class TestRouter extends \Pecee\SimpleRouter\SimpleRouter
     {
         try {
             static::debugNoReset($testUrl, $testMethod);
-        } catch(\Exception $e) {
+        } catch (\Exception $e) {
+            static::$defaultNamespace = null;
             static::router()->reset();
             throw $e;
         }
 
-        if($reset === true) {
+        if ($reset === true) {
+            static::$defaultNamespace = null;
             static::router()->reset();
         }