diff --git a/composer.json b/composer.json
index 68069fa6..adb86a44 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,7 @@
     "require-dev": {
         "phpunit/phpunit": "^7.0",
         "matthiasnoback/symfony-dependency-injection-test": "~3.0",
-        "friendsofphp/php-cs-fixer": "^2.13"
+        "friendsofphp/php-cs-fixer": "~2.15.0"
     },
     "autoload": {
         "psr-4": {
diff --git a/tests/bundle/eZ/RichText/RendererTest.php b/tests/bundle/eZ/RichText/RendererTest.php
index 5f2df5eb..f33426d3 100644
--- a/tests/bundle/eZ/RichText/RendererTest.php
+++ b/tests/bundle/eZ/RichText/RendererTest.php
@@ -48,19 +48,19 @@ public function testRenderTag()
             ->expects($this->once())
             ->method('render')
             ->with($templateName, $parameters)
-            ->will($this->returnValue($result));
+            ->willReturn($result);
 
         $renderer
             ->expects($this->once())
             ->method('getTagTemplateName')
             ->with($name, $isInline)
-            ->will($this->returnValue($templateName));
+            ->willReturn($templateName);
 
         $this->templateEngineMock
             ->expects($this->once())
             ->method('exists')
             ->with($templateName)
-            ->will($this->returnValue(true));
+            ->willReturn(true);
 
         $this->loggerMock
             ->expects($this->never())
@@ -87,7 +87,7 @@ public function testRenderTagNoTemplateConfigured()
             ->expects($this->once())
             ->method('getTagTemplateName')
             ->with($name, $isInline)
-            ->will($this->returnValue(null));
+            ->willReturn(null);
 
         $this->templateEngineMock
             ->expects($this->never())
@@ -119,13 +119,13 @@ public function testRenderTagNoTemplateFound()
             ->expects($this->once())
             ->method('getTagTemplateName')
             ->with($name, $isInline)
-            ->will($this->returnValue('templateName'));
+            ->willReturn('templateName');
 
         $this->templateEngineMock
             ->expects($this->once())
             ->method('exists')
             ->with($templateName)
-            ->will($this->returnValue(false));
+            ->willReturn(false);
 
         $this->loggerMock
             ->expects($this->once())
@@ -253,7 +253,7 @@ public function testRenderTagWithTemplate(
                 ->expects($this->once())
                 ->method('render')
                 ->with($renderTemplate, $parameters)
-                ->will($this->returnValue($renderResult));
+                ->willReturn($renderResult);
         }
 
         if (!isset($templateEngineTemplate)) {
@@ -265,7 +265,7 @@ public function testRenderTagWithTemplate(
                 ->expects($this->once())
                 ->method('exists')
                 ->with($templateEngineTemplate)
-                ->will($this->returnValue(true));
+                ->willReturn(true);
         }
 
         if (empty($configResolverParams)) {
@@ -282,7 +282,7 @@ public function testRenderTagWithTemplate(
                     ->expects($this->at($i))
                     ->method($method)
                     ->with($namespace)
-                    ->will($this->returnValue($returnValue));
+                    ->willReturn($returnValue);
                 ++$i;
             }
         }
@@ -339,19 +339,19 @@ public function testRenderContentEmbed()
             ->expects($this->once())
             ->method('render')
             ->with($templateName, $parameters)
-            ->will($this->returnValue($result));
+            ->willReturn($result);
 
         $renderer
             ->expects($this->once())
             ->method('getEmbedTemplateName')
             ->with(Renderer::RESOURCE_TYPE_CONTENT, $isInline, $isDenied)
-            ->will($this->returnValue($templateName));
+            ->willReturn($templateName);
 
         $this->templateEngineMock
             ->expects($this->once())
             ->method('exists')
             ->with($templateName)
-            ->will($this->returnValue(true));
+            ->willReturn(true);
 
         $this->loggerMock
             ->expects($this->never())
@@ -395,7 +395,7 @@ public function testRenderContentEmbedNoTemplateConfigured()
             ->expects($this->once())
             ->method('getEmbedTemplateName')
             ->with(Renderer::RESOURCE_TYPE_CONTENT, $isInline, $isDenied)
-            ->will($this->returnValue($templateName));
+            ->willReturn($templateName);
 
         $this->templateEngineMock
             ->expects($this->never())
@@ -442,13 +442,13 @@ public function testRenderContentEmbedNoTemplateFound()
             ->expects($this->once())
             ->method('getEmbedTemplateName')
             ->with(Renderer::RESOURCE_TYPE_CONTENT, $isInline, $isDenied)
-            ->will($this->returnValue($templateName));
+            ->willReturn($templateName);
 
         $this->templateEngineMock
             ->expects($this->once())
             ->method('exists')
             ->with($templateName)
-            ->will($this->returnValue(false));
+            ->willReturn(false);
 
         $this->loggerMock
             ->expects($this->once())
@@ -489,19 +489,19 @@ public function testRenderContentEmbedAccessDenied()
             ->expects($this->once())
             ->method('render')
             ->with($templateName, $parameters)
-            ->will($this->returnValue($result));
+            ->willReturn($result);
 
         $renderer
             ->expects($this->once())
             ->method('getEmbedTemplateName')
             ->with(Renderer::RESOURCE_TYPE_CONTENT, $isInline, $isDenied)
-            ->will($this->returnValue($templateName));
+            ->willReturn($templateName);
 
         $this->templateEngineMock
             ->expects($this->once())
             ->method('exists')
             ->with($templateName)
-            ->will($this->returnValue(true));
+            ->willReturn(true);
 
         $this->loggerMock
             ->expects($this->once())
@@ -802,7 +802,7 @@ public function testRenderContentWithTemplate(
                 ->expects($this->once())
                 ->method('render')
                 ->with($renderTemplate, $parameters)
-                ->will($this->returnValue($renderResult));
+                ->willReturn($renderResult);
         }
 
         if (!isset($templateEngineTemplate)) {
@@ -814,7 +814,7 @@ public function testRenderContentWithTemplate(
                 ->expects($this->once())
                 ->method('exists')
                 ->with($templateEngineTemplate)
-                ->will($this->returnValue(true));
+                ->willReturn(true);
         }
 
         if (empty($configResolverParams)) {
@@ -831,7 +831,7 @@ public function testRenderContentWithTemplate(
                     ->expects($this->at($i))
                     ->method($method)
                     ->with($namespace)
-                    ->will($this->returnValue($returnValue));
+                    ->willReturn($returnValue);
                 ++$i;
             }
         }
@@ -875,31 +875,31 @@ public function testRenderLocationEmbed()
             ->expects($this->once())
             ->method('__get')
             ->with('invisible')
-            ->will($this->returnValue(false));
+            ->willReturn(false);
 
         $renderer
             ->expects($this->once())
             ->method('checkLocation')
             ->with($locationId)
-            ->will($this->returnValue($mockLocation));
+            ->willReturn($mockLocation);
 
         $renderer
             ->expects($this->once())
             ->method('render')
             ->with($templateName, $parameters)
-            ->will($this->returnValue($result));
+            ->willReturn($result);
 
         $renderer
             ->expects($this->once())
             ->method('getEmbedTemplateName')
             ->with(Renderer::RESOURCE_TYPE_LOCATION, $isInline, $isDenied)
-            ->will($this->returnValue($templateName));
+            ->willReturn($templateName);
 
         $this->templateEngineMock
             ->expects($this->once())
             ->method('exists')
             ->with($templateName)
-            ->will($this->returnValue(true));
+            ->willReturn(true);
 
         $this->loggerMock
             ->expects($this->never())
@@ -926,13 +926,13 @@ public function testRenderLocationEmbedNoTemplateConfigured()
             ->expects($this->once())
             ->method('__get')
             ->with('invisible')
-            ->will($this->returnValue(false));
+            ->willReturn(false);
 
         $renderer
             ->expects($this->once())
             ->method('checkLocation')
             ->with($locationId)
-            ->will($this->returnValue($mockLocation));
+            ->willReturn($mockLocation);
 
         $renderer
             ->expects($this->never())
@@ -942,7 +942,7 @@ public function testRenderLocationEmbedNoTemplateConfigured()
             ->expects($this->once())
             ->method('getEmbedTemplateName')
             ->with(Renderer::RESOURCE_TYPE_LOCATION, $isInline, $isDenied)
-            ->will($this->returnValue($templateName));
+            ->willReturn($templateName);
 
         $this->templateEngineMock
             ->expects($this->never())
@@ -973,13 +973,13 @@ public function testRenderLocationEmbedNoTemplateFound()
             ->expects($this->once())
             ->method('__get')
             ->with('invisible')
-            ->will($this->returnValue(false));
+            ->willReturn(false);
 
         $renderer
             ->expects($this->once())
             ->method('checkLocation')
             ->with($locationId)
-            ->will($this->returnValue($mockLocation));
+            ->willReturn($mockLocation);
 
         $renderer
             ->expects($this->never())
@@ -989,13 +989,13 @@ public function testRenderLocationEmbedNoTemplateFound()
             ->expects($this->once())
             ->method('getEmbedTemplateName')
             ->with(Renderer::RESOURCE_TYPE_LOCATION, $isInline, $isDenied)
-            ->will($this->returnValue($templateName));
+            ->willReturn($templateName);
 
         $this->templateEngineMock
             ->expects($this->once())
             ->method('exists')
             ->with($templateName)
-            ->will($this->returnValue(false));
+            ->willReturn(false);
 
         $this->loggerMock
             ->expects($this->once())
@@ -1028,19 +1028,19 @@ public function testRenderLocationEmbedAccessDenied()
             ->expects($this->once())
             ->method('render')
             ->with($templateName, $parameters)
-            ->will($this->returnValue($result));
+            ->willReturn($result);
 
         $renderer
             ->expects($this->once())
             ->method('getEmbedTemplateName')
             ->with(Renderer::RESOURCE_TYPE_LOCATION, $isInline, $isDenied)
-            ->will($this->returnValue($templateName));
+            ->willReturn($templateName);
 
         $this->templateEngineMock
             ->expects($this->once())
             ->method('exists')
             ->with($templateName)
-            ->will($this->returnValue(true));
+            ->willReturn(true);
 
         $this->loggerMock
             ->expects($this->once())
@@ -1066,13 +1066,13 @@ public function testRenderLocationEmbedInvisible()
             ->expects($this->once())
             ->method('__get')
             ->with('invisible')
-            ->will($this->returnValue(true));
+            ->willReturn(true);
 
         $renderer
             ->expects($this->once())
             ->method('checkLocation')
             ->with($locationId)
-            ->will($this->returnValue($mockLocation));
+            ->willReturn($mockLocation);
 
         $renderer
             ->expects($this->never())
@@ -1312,13 +1312,13 @@ public function testRenderLocationWithTemplate(
                 ->expects($this->once())
                 ->method('__get')
                 ->with('invisible')
-                ->will($this->returnValue(false));
+                ->willReturn(false);
 
             $renderer
                 ->expects($this->once())
                 ->method('checkLocation')
                 ->with($locationId)
-                ->will($this->returnValue($mockLocation));
+                ->willReturn($mockLocation);
         }
 
         if (!isset($renderTemplate)) {
@@ -1330,7 +1330,7 @@ public function testRenderLocationWithTemplate(
                 ->expects($this->once())
                 ->method('render')
                 ->with($renderTemplate, $parameters)
-                ->will($this->returnValue($renderResult));
+                ->willReturn($renderResult);
         }
 
         if (!isset($templateEngineTemplate)) {
@@ -1342,7 +1342,7 @@ public function testRenderLocationWithTemplate(
                 ->expects($this->once())
                 ->method('exists')
                 ->with($templateEngineTemplate)
-                ->will($this->returnValue(true));
+                ->willReturn(true);
         }
 
         if (empty($configResolverParams)) {
@@ -1359,7 +1359,7 @@ public function testRenderLocationWithTemplate(
                     ->expects($this->at($i))
                     ->method($method)
                     ->with($namespace)
-                    ->will($this->returnValue($returnValue));
+                    ->willReturn($returnValue);
                 ++$i;
             }
         }
diff --git a/tests/lib/eZ/FieldType/RichText/RichTextStorageTest.php b/tests/lib/eZ/FieldType/RichText/RichTextStorageTest.php
index 9cd2b75f..2f53e229 100644
--- a/tests/lib/eZ/FieldType/RichText/RichTextStorageTest.php
+++ b/tests/lib/eZ/FieldType/RichText/RichTextStorageTest.php
@@ -70,7 +70,7 @@ public function testGetFieldData($xmlString, $updatedXmlString, $linkIds, $linkU
             ->expects($this->once())
             ->method('getIdUrlMap')
             ->with($this->equalTo($linkIds))
-            ->will($this->returnValue($linkUrls));
+            ->willReturn($linkUrls);
         $gateway->expects($this->never())->method('getUrlIdMap');
         $gateway->expects($this->never())->method('getContentIds');
         $gateway->expects($this->never())->method('insertUrl');
@@ -200,12 +200,12 @@ public function testStoreFieldData(
             ->expects($this->at($gatewayCallIndex++))
             ->method('getUrlIdMap')
             ->with($this->equalTo($linkUrls))
-            ->will($this->returnValue($linkIds));
+            ->willReturn($linkIds);
         $gateway
             ->expects($this->at($gatewayCallIndex++))
             ->method('getContentIds')
             ->with($this->equalTo($remoteIds))
-            ->will($this->returnValue($contentIds));
+            ->willReturn($contentIds);
         $gateway->expects($this->never())->method('getIdUrlMap');
         if (empty($insertLinks)) {
             $gateway->expects($this->never())->method('insertUrl');
@@ -218,7 +218,7 @@ public function testStoreFieldData(
                     ->expects($this->at($gatewayCallIndex++))
                     ->method('insertUrl')
                     ->with($this->equalTo($url))
-                    ->will($this->returnValue($id));
+                    ->willReturn($id);
             } else {
                 $id = $linkIds[$url];
             }
@@ -283,12 +283,12 @@ public function testStoreFieldDataThrowsNotFoundException(
             ->expects($this->once())
             ->method('getUrlIdMap')
             ->with($this->equalTo($linkUrls))
-            ->will($this->returnValue($linkIds));
+            ->willReturn($linkIds);
         $gateway
             ->expects($this->once())
             ->method('getContentIds')
             ->with($this->equalTo($remoteIds))
-            ->will($this->returnValue($contentIds));
+            ->willReturn($contentIds);
         $gateway->expects($this->never())->method('getIdUrlMap');
         if (empty($insertLinks)) {
             $gateway->expects($this->never())->method('insertUrl');
@@ -299,7 +299,7 @@ public function testStoreFieldDataThrowsNotFoundException(
                 ->expects($this->at($index + 2))
                 ->method('insertUrl')
                 ->with($this->equalTo($linkMap['url']))
-                ->will($this->returnValue($linkMap['id']));
+                ->willReturn($linkMap['id']);
         }
 
         $versionInfo = new VersionInfo();
diff --git a/tests/lib/eZ/REST/FieldTypeProcessor/RichTextProcessorTest.php b/tests/lib/eZ/REST/FieldTypeProcessor/RichTextProcessorTest.php
index 773c121f..36262d81 100644
--- a/tests/lib/eZ/REST/FieldTypeProcessor/RichTextProcessorTest.php
+++ b/tests/lib/eZ/REST/FieldTypeProcessor/RichTextProcessorTest.php
@@ -45,7 +45,7 @@ public function testPostProcessValueHash()
             ->expects($this->once())
             ->method('convert')
             ->with($this->isInstanceOf('DOMDocument'))
-            ->will($this->returnValue($convertedDocument));
+            ->willReturn($convertedDocument);
 
         $this->assertEquals(
             $processedOutputValue,
diff --git a/tests/lib/eZ/RichText/Converter/LinkTest.php b/tests/lib/eZ/RichText/Converter/LinkTest.php
index 4385d184..36ad0da6 100644
--- a/tests/lib/eZ/RichText/Converter/LinkTest.php
+++ b/tests/lib/eZ/RichText/Converter/LinkTest.php
@@ -222,12 +222,12 @@ public function testConvertLocationLink($input, $output, $locationId, $urlResolv
         $locationService->expects($this->once())
             ->method('loadLocation')
             ->with($this->equalTo($locationId))
-            ->will($this->returnValue($location));
+            ->willReturn($location);
 
         $urlAliasRouter->expects($this->once())
             ->method('generate')
             ->with($this->equalTo($location))
-            ->will($this->returnValue($urlResolved));
+            ->willReturn($urlResolved);
 
         $converter = new Link($locationService, $contentService, $urlAliasRouter);
 
@@ -427,22 +427,22 @@ public function testConvertContentLink($input, $output, $contentId, $urlResolved
         $contentInfo->expects($this->once())
             ->method('__get')
             ->with($this->equalTo('mainLocationId'))
-            ->will($this->returnValue($locationId));
+            ->willReturn($locationId);
 
         $contentService->expects($this->any())
             ->method('loadContentInfo')
             ->with($this->equalTo($contentId))
-            ->will($this->returnValue($contentInfo));
+            ->willReturn($contentInfo);
 
         $locationService->expects($this->once())
             ->method('loadLocation')
             ->with($this->equalTo($locationId))
-            ->will($this->returnValue($location));
+            ->willReturn($location);
 
         $urlAliasRouter->expects($this->once())
             ->method('generate')
             ->with($this->equalTo($location))
-            ->will($this->returnValue($urlResolved));
+            ->willReturn($urlResolved);
 
         $converter = new Link($locationService, $contentService, $urlAliasRouter);
 
diff --git a/tests/lib/eZ/RichText/Converter/Render/EmbedTest.php b/tests/lib/eZ/RichText/Converter/Render/EmbedTest.php
index 9146d38e..fdfd0c53 100644
--- a/tests/lib/eZ/RichText/Converter/Render/EmbedTest.php
+++ b/tests/lib/eZ/RichText/Converter/Render/EmbedTest.php
@@ -494,7 +494,7 @@ public function testConvert($xmlString, $expectedXmlString, array $errors, array
                         ],
                         $params['is_inline']
                     )
-                    ->will($this->returnValue($params['id']));
+                    ->willReturn($params['id']);
             }
         } else {
             $this->rendererMock->expects($this->never())->method('renderContentEmbed');
diff --git a/tests/lib/eZ/RichText/Converter/Render/TemplateTest.php b/tests/lib/eZ/RichText/Converter/Render/TemplateTest.php
index 097d8069..e448e94d 100644
--- a/tests/lib/eZ/RichText/Converter/Render/TemplateTest.php
+++ b/tests/lib/eZ/RichText/Converter/Render/TemplateTest.php
@@ -107,7 +107,7 @@ public function testConvert(DOMDocument $inputDocument, DOMDocument $expectedOut
                         ->expects($this->at($convertIndex++))
                         ->method('convert')
                         ->with($contentDoc)
-                        ->will($this->returnValue($contentDoc));
+                        ->willReturn($contentDoc);
                 }
 
                 $this->rendererMock
@@ -119,7 +119,7 @@ public function testConvert(DOMDocument $inputDocument, DOMDocument $expectedOut
                         $params['params'],
                         $params['is_inline']
                     )
-                    ->will($this->returnValue($params['name']));
+                    ->willReturn($params['name']);
             }
         } else {
             $this->rendererMock->expects($this->never())->method('renderTemplate');