diff --git a/.gitignore b/.gitignore
index d157f2c..6980ff2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@ phpunit.xml
 composer.lock
 .php_cs
 .php_cs.cache
+phpstan.neon
\ No newline at end of file
diff --git a/.travis.yml b/.travis.yml
index 24d3263..4ea660a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -43,6 +43,8 @@ matrix:
           env: TWIG_VERSION=1.*
         - php: 7.0
           env: TWIG_VERSION=2.*
+        - php: 7.1
+          env: PHPSTAN_VERSION=0.11.*
 
 before_install:
     - if [ -n "$GH_TOKEN" ]; then composer config github-oauth.github.com ${GH_TOKEN}; fi;
@@ -52,9 +54,11 @@ before_script:
     - if [ "$DOCTRINE_VERSION" != "" ]; then composer require "doctrine/orm:${DOCTRINE_VERSION}" --dev --no-update; fi;
     - if [ "$TWIG_VERSION" != "" ]; then composer require "twig/twig:${TWIG_VERSION}" --dev --no-update; fi;
     - if [ "$PHPUNIT_VERSION" != "" ]; then composer require "phpunit/phpunit:${PHPUNIT_VERSION}" --dev --no-update; fi;
+    - if [ "$PHPSTAN_VERSION" != "" ]; then composer require "phpstan/phpstan:${PHPSTAN_VERSION}" --dev --no-update; fi;
     - COMPOSER_MEMORY_LIMIT=-1 composer install --prefer-dist --no-interaction --no-scripts --no-progress
 
 script:
+    - if [ "$PHPSTAN_VERSION" != "" ]; then ./vendor/bin/phpstan analyse; fi;
     - vendor/bin/phpunit --coverage-clover build/coverage-clover.xml
 
 after_script:
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
new file mode 100644
index 0000000..1d5823a
--- /dev/null
+++ b/phpstan.neon.dist
@@ -0,0 +1,4 @@
+parameters:
+    level: 7
+    paths:
+        - src
diff --git a/src/DependencyInjection/Configuration.php b/src/DependencyInjection/Configuration.php
index 2faddc5..a8e8aee 100644
--- a/src/DependencyInjection/Configuration.php
+++ b/src/DependencyInjection/Configuration.php
@@ -10,6 +10,7 @@
 
 namespace GpsLab\Bundle\PaginationBundle\DependencyInjection;
 
+use Symfony\Component\Config\Definition\Builder\ArrayNodeDefinition;
 use Symfony\Component\Config\Definition\Builder\TreeBuilder;
 use Symfony\Component\Config\Definition\ConfigurationInterface;
 
@@ -30,19 +31,20 @@ public function getConfigTreeBuilder()
             $root = $tree_builder->root('gpslab_pagination');
         }
 
-        $root
-            ->addDefaultsIfNotSet()
-            ->children()
-                ->scalarNode('max_navigate')
-                    ->defaultValue(5)
-                ->end()
-                ->scalarNode('parameter_name')
-                    ->defaultValue('page')
-                ->end()
-                ->scalarNode('template')
-                    ->defaultValue('GpsLabPaginationBundle::pagination.html.twig')
-                ->end()
-            ->end();
+        // @codeCoverageIgnoreStart
+        if (!$root instanceof ArrayNodeDefinition) {
+            throw new \RuntimeException(sprintf(
+                'Config root node must be a "%s", given "%s".',
+                'Symfony\Component\Config\Definition\Builder\ArrayNodeDefinition',
+                get_class($root)
+            ));
+        }
+        // @codeCoverageIgnoreEnd
+
+        $root->addDefaultsIfNotSet();
+        $root->children()->scalarNode('max_navigate')->defaultValue(5);
+        $root->children()->scalarNode('parameter_name')->defaultValue('page');
+        $root->children()->scalarNode('template')->defaultValue('GpsLabPaginationBundle::pagination.html.twig');
 
         return $tree_builder;
     }
diff --git a/src/Service/Builder.php b/src/Service/Builder.php
index f28442b..4c05835 100644
--- a/src/Service/Builder.php
+++ b/src/Service/Builder.php
@@ -10,7 +10,6 @@
 
 namespace GpsLab\Bundle\PaginationBundle\Service;
 
-use Doctrine\ORM\NonUniqueResultException;
 use Doctrine\ORM\QueryBuilder;
 use GpsLab\Bundle\PaginationBundle\Exception\IncorrectPageNumberException;
 use GpsLab\Bundle\PaginationBundle\Exception\OutOfRangeException;
@@ -70,8 +69,6 @@ public function paginate($total_pages = 1, $current_page = 1)
      * @param int          $per_page     Entities per page
      * @param int          $current_page The current page number
      *
-     * @throws NonUniqueResultException
-     *
      * @return Configuration
      */
     public function paginateQuery(QueryBuilder $query, $per_page, $current_page = 1)
@@ -83,7 +80,7 @@ public function paginateQuery(QueryBuilder $query, $per_page, $current_page = 1)
             ->getSingleScalarResult()
         ;
 
-        $total_pages = ceil($total / $per_page);
+        $total_pages = (int) ceil($total / $per_page);
         $current_page = $this->validateCurrentPage($current_page, $total_pages);
 
         $query
@@ -126,8 +123,6 @@ public function paginateRequest(
      * @param string       $parameter_name Name of URL parameter for page number
      * @param int          $reference_type The type of reference (one of the constants in UrlGeneratorInterface)
      *
-     * @throws NonUniqueResultException
-     *
      * @return Configuration
      */
     public function paginateRequestQuery(
@@ -159,12 +154,12 @@ private function validateCurrentPage($current_page, $total_pages)
             return 1;
         }
 
-        if (!is_numeric($current_page)) {
+        if (!is_int($current_page) && (!is_string($current_page) || !ctype_digit($current_page))) {
             throw IncorrectPageNumberException::incorrect($current_page);
         }
 
         if ($current_page < 1 || $current_page > $total_pages) {
-            throw OutOfRangeException::out($current_page, $total_pages);
+            throw OutOfRangeException::out((int) $current_page, $total_pages);
         }
 
         return (int) $current_page;
@@ -185,7 +180,7 @@ private function configureFromRequest(
         $reference_type
     ) {
         $route = $request->get('_route');
-        $route_params = array_merge($request->query->all(), $request->get('_route_params'));
+        $route_params = array_merge($request->query->all(), $request->get('_route_params', []));
         unset($route_params[$parameter_name]);
 
         return $configuration
diff --git a/src/Service/Configuration.php b/src/Service/Configuration.php
index f25e3c7..17c3626 100644
--- a/src/Service/Configuration.php
+++ b/src/Service/Configuration.php
@@ -35,7 +35,7 @@ class Configuration
     private $current_page = 1;
 
     /**
-     * @var View
+     * @var View|null
      */
     private $view;
 
diff --git a/src/Service/NavigateRange.php b/src/Service/NavigateRange.php
index 62b6cb2..89ceb24 100644
--- a/src/Service/NavigateRange.php
+++ b/src/Service/NavigateRange.php
@@ -81,9 +81,9 @@ private function definitionOffset()
     private function adjustmentLargeLeftOffset()
     {
         if ($this->config->getCurrentPage() - $this->left_offset < 1) {
-            $offset = (int) abs($this->config->getCurrentPage() - 1 - $this->left_offset);
-            $this->left_offset = $this->left_offset - $offset;
-            $this->right_offset = $this->right_offset + $offset;
+            $offset = abs($this->config->getCurrentPage() - 1 - $this->left_offset);
+            $this->left_offset -= $offset;
+            $this->right_offset += $offset;
         }
     }
 
@@ -93,13 +93,13 @@ private function adjustmentLargeLeftOffset()
     private function adjustmentLargeRightOffset()
     {
         if ($this->config->getCurrentPage() + $this->right_offset > $this->config->getTotalPages()) {
-            $offset = (int) abs(
+            $offset = abs(
                 $this->config->getTotalPages() -
                 $this->config->getCurrentPage() -
                 $this->right_offset
             );
-            $this->left_offset = $this->left_offset + $offset;
-            $this->right_offset = $this->right_offset - $offset;
+            $this->left_offset += $offset;
+            $this->right_offset -= $offset;
         }
     }
 
diff --git a/src/Service/View.php b/src/Service/View.php
index 5968f80..af86d7d 100644
--- a/src/Service/View.php
+++ b/src/Service/View.php
@@ -36,7 +36,7 @@ class View implements \IteratorAggregate
     private $prev;
 
     /**
-     * @var Node
+     * @var Node|null
      */
     private $current;
 
@@ -144,7 +144,7 @@ public function getLast()
     }
 
     /**
-     * @return ArrayCollection
+     * @return ArrayCollection|Node[]
      */
     public function getIterator()
     {
diff --git a/tests/Service/BuilderTest.php b/tests/Service/BuilderTest.php
index 3b0ed18..ec26ebb 100644
--- a/tests/Service/BuilderTest.php
+++ b/tests/Service/BuilderTest.php
@@ -15,7 +15,6 @@
 use GpsLab\Bundle\PaginationBundle\Service\Builder;
 use GpsLab\Bundle\PaginationBundle\Tests\TestCase;
 use Symfony\Bundle\FrameworkBundle\Routing\Router;
-use Symfony\Component\HttpFoundation\ParameterBag;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 
@@ -26,11 +25,6 @@ class BuilderTest extends TestCase
      */
     private $router;
 
-    /**
-     * @var \PHPUnit_Framework_MockObject_MockObject|Request
-     */
-    private $request;
-
     /**
      * @var \PHPUnit_Framework_MockObject_MockObject|AbstractQuery
      */
@@ -41,6 +35,11 @@ class BuilderTest extends TestCase
      */
     private $query_builder;
 
+    /**
+     * @var Request
+     */
+    private $request;
+
     /**
      * @var array
      */
@@ -52,11 +51,10 @@ class BuilderTest extends TestCase
     protected function setUp()
     {
         $this->router = $this->getMockNoConstructor('Symfony\Bundle\FrameworkBundle\Routing\Router');
-        $this->request = $this->getMockNoConstructor('Symfony\Component\HttpFoundation\Request');
         $this->query = $this->getMockAbstract('Doctrine\ORM\AbstractQuery', ['getSingleScalarResult']);
         $this->query_builder = $this->getMockNoConstructor('Doctrine\ORM\QueryBuilder');
 
-        $this->request->query = new ParameterBag($this->query_params);
+        $this->request = new Request($this->query_params);
     }
 
     public function testDefaultPageLink()
@@ -158,7 +156,9 @@ public function testPaginateQueryOutOfRange()
      */
     public function testPaginateRequestIncorrectPage()
     {
-        $this->currentPage('foo', 'page');
+        $this->request = new Request(array_merge($this->query_params, [
+            'page' => 'foo',
+        ]));
 
         $builder = new Builder($this->router, 5, 'page');
         $builder->paginateRequest($this->request, 10);
@@ -169,7 +169,9 @@ public function testPaginateRequestIncorrectPage()
      */
     public function testPaginateRequestLowPageNumber()
     {
-        $this->currentPage(0, 'p');
+        $this->request = new Request(array_merge($this->query_params, [
+            'p' => 0,
+        ]));
 
         $builder = new Builder($this->router, 5, 'page');
         $builder->paginateRequest($this->request, 10, 'p');
@@ -180,7 +182,9 @@ public function testPaginateRequestLowPageNumber()
      */
     public function testPaginateRequestOutOfRange()
     {
-        $this->currentPage(150, 'p');
+        $this->request = new Request(array_merge($this->query_params, [
+            'p' => 150,
+        ]));
 
         $builder = new Builder($this->router, 5, 'page');
         $builder->paginateRequest($this->request, 10, 'p');
@@ -195,20 +199,12 @@ public function testPaginateRequest()
         $route_params = ['foo' => 'baz', '_route_params' => 123];
         $all_params = array_merge($this->query_params, $route_params);
         $reference_type = UrlGeneratorInterface::ABSOLUTE_URL;
-
-        $this->currentPage(null, 'p');
-        $this->request
-            ->expects($this->at(1))
-            ->method('get')
-            ->with('_route')
-            ->willReturn($route)
-        ;
-        $this->request
-            ->expects($this->at(2))
-            ->method('get')
-            ->with('_route_params')
-            ->willReturn($route_params)
-        ;
+        $this->request = new Request(array_merge($this->query_params, [
+            'p' => null,
+        ]), [], [
+            '_route' => $route,
+            '_route_params' => $route_params,
+        ]);
 
         $that = $this;
         $this->router
@@ -247,7 +243,9 @@ public function testPaginateRequest()
      */
     public function testPaginateRequesQuerytIncorrectPage()
     {
-        $this->currentPage('foo', 'page');
+        $this->request = new Request(array_merge($this->query_params, [
+            'page' => 'foo',
+        ]));
         $this->countQuery(10);
 
         $builder = new Builder($this->router, 5, 'page');
@@ -259,7 +257,9 @@ public function testPaginateRequesQuerytIncorrectPage()
      */
     public function testPaginateRequestQueryLowPageNumber()
     {
-        $this->currentPage(0, 'p');
+        $this->request = new Request(array_merge($this->query_params, [
+            'p' => 0,
+        ]));
         $this->countQuery(10);
 
         $builder = new Builder($this->router, 5, 'page');
@@ -271,7 +271,9 @@ public function testPaginateRequestQueryLowPageNumber()
      */
     public function testPaginateRequestQueryOutOfRange()
     {
-        $this->currentPage(150, 'p');
+        $this->request = new Request(array_merge($this->query_params, [
+            'p' => 150,
+        ]));
         $this->countQuery(10);
 
         $builder = new Builder($this->router, 5, 'page');
@@ -289,20 +291,12 @@ public function testPaginateRequestQuery()
         $route_params = ['foo' => 'baz', '_route_params'];
         $all_params = array_merge($this->query_params, $route_params);
         $reference_type = UrlGeneratorInterface::ABSOLUTE_URL;
-
-        $this->currentPage($current_page, 'p');
-        $this->request
-            ->expects($this->at(1))
-            ->method('get')
-            ->with('_route')
-            ->willReturn($route)
-        ;
-        $this->request
-            ->expects($this->at(2))
-            ->method('get')
-            ->with('_route_params')
-            ->willReturn($route_params)
-        ;
+        $this->request = new Request(array_merge($this->query_params, [
+            'p' => $current_page,
+        ]), [], [
+            '_route' => $route,
+            '_route_params' => $route_params,
+        ]);
 
         $this->countQuery($total);
         $this->query_builder
@@ -356,20 +350,6 @@ public function testPaginateRequestQuery()
         );
     }
 
-    /**
-     * @param int    $current_page
-     * @param string $parameter_name
-     */
-    private function currentPage($current_page, $parameter_name = 'page')
-    {
-        $this->request
-            ->expects($this->at(0))
-            ->method('get')
-            ->with($parameter_name)
-            ->willReturn($current_page)
-        ;
-    }
-
     /**
      * @param int $total
      */
diff --git a/tests/Service/ConfigurationTest.php b/tests/Service/ConfigurationTest.php
index fc9b8ce..db24880 100644
--- a/tests/Service/ConfigurationTest.php
+++ b/tests/Service/ConfigurationTest.php
@@ -18,7 +18,7 @@ class ConfigurationTest extends TestCase
     /**
      * @var Configuration
      */
-    protected $config;
+    private $config;
 
     protected function setUp()
     {
diff --git a/tests/Service/NavigateRangeTest.php b/tests/Service/NavigateRangeTest.php
index aec436d..de95a89 100644
--- a/tests/Service/NavigateRangeTest.php
+++ b/tests/Service/NavigateRangeTest.php
@@ -19,12 +19,12 @@ class NavigateRangeTest extends TestCase
     /**
      * @var \PHPUnit_Framework_MockObject_MockObject|Configuration
      */
-    protected $config;
+    private $config;
 
     /**
      * @var NavigateRange
      */
-    protected $range;
+    private $range;
 
     protected function setUp()
     {
diff --git a/tests/Service/ViewTest.php b/tests/Service/ViewTest.php
index fe0cd2d..a0d91b7 100644
--- a/tests/Service/ViewTest.php
+++ b/tests/Service/ViewTest.php
@@ -22,17 +22,17 @@ class ViewTest extends TestCase
     /**
      * @var \PHPUnit_Framework_MockObject_MockObject|Configuration
      */
-    protected $config;
+    private $config;
 
     /**
      * @var \PHPUnit_Framework_MockObject_MockObject|NavigateRange
      */
-    protected $range;
+    private $range;
 
     /**
      * @var View
      */
-    protected $view;
+    private $view;
 
     protected function setUp()
     {
diff --git a/tests/TestCase.php b/tests/TestCase.php
index 44e3911..c48e8ea 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -23,8 +23,7 @@ protected function getMockNoConstructor($class_name)
             ->getMockBuilder($class_name)
             ->disableOriginalConstructor()
             ->disableOriginalClone()
-            ->getMock()
-        ;
+            ->getMock();
     }
 
     /**
@@ -39,7 +38,6 @@ protected function getMockAbstract($class_name, array $methods)
             ->getMockBuilder($class_name)
             ->disableOriginalConstructor()
             ->setMethods($methods)
-            ->getMockForAbstractClass()
-        ;
+            ->getMockForAbstractClass();
     }
 }
diff --git a/tests/Twig/Extension/PaginationExtensionTest.php b/tests/Twig/Extension/PaginationExtensionTest.php
index aba496a..27727a6 100644
--- a/tests/Twig/Extension/PaginationExtensionTest.php
+++ b/tests/Twig/Extension/PaginationExtensionTest.php
@@ -19,12 +19,12 @@ class PaginationExtensionTest extends TestCase
     /**
      * @var PaginationExtension
      */
-    protected $extension;
+    private $extension;
 
     /**
      * @var string
      */
-    protected $template = 'foo';
+    private $template = 'foo';
 
     protected function setUp()
     {