diff --git a/src/CSSList/AtRuleBlockList.php b/src/CSSList/AtRuleBlockList.php
index be233f84..ecf3762d 100644
--- a/src/CSSList/AtRuleBlockList.php
+++ b/src/CSSList/AtRuleBlockList.php
@@ -2,6 +2,7 @@
 
 namespace Sabberworm\CSS\CSSList;
 
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Property\AtRule;
 
 /**
@@ -49,13 +50,13 @@ public function atRuleArgs()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         $sArgs = $this->sArgs;
         if ($sArgs) {
diff --git a/src/CSSList/CSSList.php b/src/CSSList/CSSList.php
index 8ad7300a..0ec08886 100644
--- a/src/CSSList/CSSList.php
+++ b/src/CSSList/CSSList.php
@@ -3,6 +3,7 @@
 namespace Sabberworm\CSS\CSSList;
 
 use Sabberworm\CSS\Comment\Commentable;
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Parsing\ParserState;
 use Sabberworm\CSS\Parsing\SourceException;
 use Sabberworm\CSS\Parsing\UnexpectedTokenException;
@@ -353,13 +354,13 @@ public function removeDeclarationBlockBySelector($mSelector, $bRemoveAll = false
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         $sResult = '';
         $bIsFirst = true;
diff --git a/src/CSSList/Document.php b/src/CSSList/Document.php
index ee30d9af..53490133 100644
--- a/src/CSSList/Document.php
+++ b/src/CSSList/Document.php
@@ -2,7 +2,9 @@
 
 namespace Sabberworm\CSS\CSSList;
 
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Parsing\ParserState;
+use Sabberworm\CSS\Parsing\SourceException;
 
 /**
  * The root CSSList of a parsed file. Contains all top-level css contents, mostly declaration blocks,
@@ -25,7 +27,7 @@ public function __construct($iLineNo = 0)
      *
      * @return Document
      *
-     * @throws \Sabberworm\CSS\Parsing\SourceException
+     * @throws SourceException
      */
     public static function parse(ParserState $oParserState)
     {
@@ -127,14 +129,14 @@ public function createShorthands()
     /**
      * Override render() to make format argument optional
      *
-     * @param \Sabberworm\CSS\OutputFormat|null $oOutputFormat
+     * @param OutputFormat|null $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat = null)
+    public function render(OutputFormat $oOutputFormat = null)
     {
         if ($oOutputFormat === null) {
-            $oOutputFormat = new \Sabberworm\CSS\OutputFormat();
+            $oOutputFormat = new OutputFormat();
         }
         return parent::render($oOutputFormat);
     }
diff --git a/src/CSSList/KeyFrame.php b/src/CSSList/KeyFrame.php
index 3a81bf86..4550cf6b 100644
--- a/src/CSSList/KeyFrame.php
+++ b/src/CSSList/KeyFrame.php
@@ -2,6 +2,7 @@
 
 namespace Sabberworm\CSS\CSSList;
 
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Property\AtRule;
 
 class KeyFrame extends CSSList implements AtRule
@@ -45,15 +46,15 @@ public function getAnimationName()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         $sResult = "@{$this->vendorKeyFrame} {$this->animationName}{$oOutputFormat->spaceBeforeOpeningBrace()}{";
         $sResult .= parent::render($oOutputFormat);
diff --git a/src/Comment/Comment.php b/src/Comment/Comment.php
index 56606f48..555130e2 100644
--- a/src/Comment/Comment.php
+++ b/src/Comment/Comment.php
@@ -2,6 +2,7 @@
 
 namespace Sabberworm\CSS\Comment;
 
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Renderable;
 
 class Comment implements Renderable
@@ -45,13 +46,13 @@ public function setComment($sComment)
      */
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         return '/*' . $this->sComment . '*/';
     }
diff --git a/src/OutputFormatter.php b/src/OutputFormatter.php
index 562d2a84..50a2fe22 100644
--- a/src/OutputFormatter.php
+++ b/src/OutputFormatter.php
@@ -123,7 +123,7 @@ public function implode($sSeparator, array $aValues, $bIncreaseLevel = false)
             } else {
                 $sResult .= $sSeparator;
             }
-            if ($mValue instanceof \Sabberworm\CSS\Renderable) {
+            if ($mValue instanceof Renderable) {
                 $sResult .= $mValue->render($oFormat);
             } else {
                 $sResult .= $mValue;
diff --git a/src/Property/CSSNamespace.php b/src/Property/CSSNamespace.php
index 24ab27f7..30957970 100644
--- a/src/Property/CSSNamespace.php
+++ b/src/Property/CSSNamespace.php
@@ -2,6 +2,8 @@
 
 namespace Sabberworm\CSS\Property;
 
+use Sabberworm\CSS\OutputFormat;
+
 /**
  * CSSNamespace represents an @namespace rule.
  */
@@ -33,15 +35,15 @@ public function getLineNo()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         return '@namespace ' . ($this->sPrefix === null ? '' : $this->sPrefix . ' ')
             . $this->mUrl->render($oOutputFormat) . ';';
diff --git a/src/Property/Charset.php b/src/Property/Charset.php
index 45dfc671..ea6be495 100644
--- a/src/Property/Charset.php
+++ b/src/Property/Charset.php
@@ -2,6 +2,8 @@
 
 namespace Sabberworm\CSS\Property;
 
+use Sabberworm\CSS\OutputFormat;
+
 /**
  * Class representing an @charset rule.
  * The following restrictions apply:
@@ -57,15 +59,15 @@ public function getCharset()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         return "@charset {$this->sCharset->render($oOutputFormat)};";
     }
diff --git a/src/Property/Import.php b/src/Property/Import.php
index 995d8c7c..72d1396b 100644
--- a/src/Property/Import.php
+++ b/src/Property/Import.php
@@ -2,6 +2,7 @@
 
 namespace Sabberworm\CSS\Property;
 
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Value\URL;
 
 /**
@@ -62,15 +63,15 @@ public function getLocation()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         return "@import " . $this->oLocation->render($oOutputFormat)
             . ($this->sMediaQuery === null ? '' : ' ' . $this->sMediaQuery) . ';';
diff --git a/src/Renderable.php b/src/Renderable.php
index 2f88f3a5..c21bf19e 100644
--- a/src/Renderable.php
+++ b/src/Renderable.php
@@ -14,7 +14,7 @@ public function __toString();
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat);
+    public function render(OutputFormat $oOutputFormat);
 
     public function getLineNo();
 }
diff --git a/src/Rule/Rule.php b/src/Rule/Rule.php
index 09873a6f..29fbc2e8 100644
--- a/src/Rule/Rule.php
+++ b/src/Rule/Rule.php
@@ -3,6 +3,7 @@
 namespace Sabberworm\CSS\Rule;
 
 use Sabberworm\CSS\Comment\Commentable;
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Parsing\ParserState;
 use Sabberworm\CSS\Renderable;
 use Sabberworm\CSS\Value\RuleValueList;
@@ -238,15 +239,15 @@ public function getIsImportant()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         $sResult = "{$this->sRule}:{$oOutputFormat->spaceAfterRuleName()}";
         if ($this->mValue instanceof Value) { //Can also be a ValueList
diff --git a/src/RuleSet/AtRuleSet.php b/src/RuleSet/AtRuleSet.php
index 20c906b5..80370053 100644
--- a/src/RuleSet/AtRuleSet.php
+++ b/src/RuleSet/AtRuleSet.php
@@ -2,6 +2,7 @@
 
 namespace Sabberworm\CSS\RuleSet;
 
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Property\AtRule;
 
 /**
@@ -49,15 +50,15 @@ public function atRuleArgs()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         $sArgs = $this->sArgs;
         if ($sArgs) {
diff --git a/src/RuleSet/DeclarationBlock.php b/src/RuleSet/DeclarationBlock.php
index 28e07c8d..1c3b661d 100644
--- a/src/RuleSet/DeclarationBlock.php
+++ b/src/RuleSet/DeclarationBlock.php
@@ -3,6 +3,7 @@
 namespace Sabberworm\CSS\RuleSet;
 
 use Sabberworm\CSS\CSSList\KeyFrame;
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Parsing\OutputException;
 use Sabberworm\CSS\Parsing\ParserState;
 use Sabberworm\CSS\Parsing\UnexpectedTokenException;
@@ -728,17 +729,17 @@ public function createFontShorthand()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      *
      * @throws OutputException
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         if (count($this->aSelectors) === 0) {
             // If all the selectors have been removed, this declaration block becomes invalid
diff --git a/src/RuleSet/RuleSet.php b/src/RuleSet/RuleSet.php
index ff36ea1d..7fcb64c2 100644
--- a/src/RuleSet/RuleSet.php
+++ b/src/RuleSet/RuleSet.php
@@ -3,6 +3,7 @@
 namespace Sabberworm\CSS\RuleSet;
 
 use Sabberworm\CSS\Comment\Commentable;
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Parsing\ParserState;
 use Sabberworm\CSS\Parsing\UnexpectedTokenException;
 use Sabberworm\CSS\Renderable;
@@ -225,15 +226,15 @@ public function removeRule($mRule)
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         $sResult = '';
         $bIsFirst = true;
diff --git a/src/Value/CSSFunction.php b/src/Value/CSSFunction.php
index 5688a93b..98cbf02e 100644
--- a/src/Value/CSSFunction.php
+++ b/src/Value/CSSFunction.php
@@ -2,6 +2,8 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\OutputFormat;
+
 class CSSFunction extends ValueList
 {
     protected $sName;
@@ -37,15 +39,15 @@ public function getArguments()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         $aArguments = parent::render($oOutputFormat);
         return "{$this->sName}({$aArguments})";
diff --git a/src/Value/CSSString.php b/src/Value/CSSString.php
index de43bc23..bf99461f 100644
--- a/src/Value/CSSString.php
+++ b/src/Value/CSSString.php
@@ -2,6 +2,7 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Parsing\ParserState;
 use Sabberworm\CSS\Parsing\SourceException;
 
@@ -62,15 +63,15 @@ public function getString()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         $sString = addslashes($this->sString);
         $sString = str_replace("\n", '\A', $sString);
diff --git a/src/Value/CalcRuleValueList.php b/src/Value/CalcRuleValueList.php
index 79e0cbcf..d44f0acb 100644
--- a/src/Value/CalcRuleValueList.php
+++ b/src/Value/CalcRuleValueList.php
@@ -2,6 +2,8 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\OutputFormat;
+
 class CalcRuleValueList extends RuleValueList
 {
     public function __construct($iLineNo = 0)
@@ -10,11 +12,11 @@ public function __construct($iLineNo = 0)
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         return $oOutputFormat->implode(' ', $this->aComponents);
     }
diff --git a/src/Value/Color.php b/src/Value/Color.php
index 0aa5c096..f3f2b29c 100644
--- a/src/Value/Color.php
+++ b/src/Value/Color.php
@@ -2,6 +2,7 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Parsing\ParserState;
 
 class Color extends CSSFunction
@@ -106,15 +107,15 @@ public function getColorDescription()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         // Shorthand RGB color values
         if ($oOutputFormat->getRGBHashNotation() && implode('', array_keys($this->aComponents)) === 'rgb') {
diff --git a/src/Value/LineName.php b/src/Value/LineName.php
index 8bd991b9..1fdd9507 100644
--- a/src/Value/LineName.php
+++ b/src/Value/LineName.php
@@ -2,6 +2,7 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Parsing\ParserState;
 use Sabberworm\CSS\Parsing\UnexpectedTokenException;
 
@@ -37,16 +38,16 @@ public static function parse(ParserState $oParserState)
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
-        return '[' . parent::render(\Sabberworm\CSS\OutputFormat::createCompact()) . ']';
+        return '[' . parent::render(OutputFormat::createCompact()) . ']';
     }
 }
diff --git a/src/Value/Size.php b/src/Value/Size.php
index ea6d717d..f07b8e91 100644
--- a/src/Value/Size.php
+++ b/src/Value/Size.php
@@ -2,6 +2,7 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Parsing\ParserState;
 
 class Size extends PrimitiveValue
@@ -142,15 +143,15 @@ public function isRelative()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         $l = localeconv();
         $sPoint = preg_quote($l['decimal_point'], '/');
diff --git a/src/Value/URL.php b/src/Value/URL.php
index c2a3a908..31d86819 100644
--- a/src/Value/URL.php
+++ b/src/Value/URL.php
@@ -2,6 +2,7 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Parsing\ParserState;
 
 class URL extends PrimitiveValue
@@ -43,15 +44,15 @@ public function getURL()
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         return "url({$this->oURL->render($oOutputFormat)})";
     }
diff --git a/src/Value/ValueList.php b/src/Value/ValueList.php
index 77197711..c7156089 100644
--- a/src/Value/ValueList.php
+++ b/src/Value/ValueList.php
@@ -2,6 +2,8 @@
 
 namespace Sabberworm\CSS\Value;
 
+use Sabberworm\CSS\OutputFormat;
+
 abstract class ValueList extends Value
 {
     protected $aComponents;
@@ -48,15 +50,15 @@ public function setListSeparator($sSeparator)
 
     public function __toString()
     {
-        return $this->render(new \Sabberworm\CSS\OutputFormat());
+        return $this->render(new OutputFormat());
     }
 
     /**
-     * @param \Sabberworm\CSS\OutputFormat $oOutputFormat
+     * @param OutputFormat $oOutputFormat
      *
      * @return string
      */
-    public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat)
+    public function render(OutputFormat $oOutputFormat)
     {
         return $oOutputFormat->implode(
             $oOutputFormat->spaceBeforeListArgumentSeparator($this->sSeparator) . $this->sSeparator
diff --git a/tests/CSSList/AtRuleBlockListTest.php b/tests/CSSList/AtRuleBlockListTest.php
index e8662d88..4e9b80c6 100644
--- a/tests/CSSList/AtRuleBlockListTest.php
+++ b/tests/CSSList/AtRuleBlockListTest.php
@@ -2,9 +2,10 @@
 
 namespace Sabberworm\CSS\Tests\CSSList;
 
+use PHPUnit\Framework\TestCase;
 use Sabberworm\CSS\Parser;
 
-class AtRuleBlockListTest extends \PHPUnit\Framework\TestCase
+class AtRuleBlockListTest extends TestCase
 {
     public function testMediaQueries()
     {
diff --git a/tests/CSSList/DocumentTest.php b/tests/CSSList/DocumentTest.php
index 6c632f1d..7361f6ac 100644
--- a/tests/CSSList/DocumentTest.php
+++ b/tests/CSSList/DocumentTest.php
@@ -2,9 +2,10 @@
 
 namespace Sabberworm\CSS\Tests\CSSList;
 
+use PHPUnit\Framework\TestCase;
 use Sabberworm\CSS\Parser;
 
-class DocumentTest extends \PHPUnit\Framework\TestCase
+class DocumentTest extends TestCase
 {
     public function testOverrideContents()
     {
diff --git a/tests/OutputFormatTest.php b/tests/OutputFormatTest.php
index 13ccd704..b447235f 100644
--- a/tests/OutputFormatTest.php
+++ b/tests/OutputFormatTest.php
@@ -2,10 +2,11 @@
 
 namespace Sabberworm\CSS\Tests;
 
+use PHPUnit\Framework\TestCase;
 use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Parser;
 
-class OutputFormatTest extends \PHPUnit\Framework\TestCase
+class OutputFormatTest extends TestCase
 {
     /**
      * @var string
diff --git a/tests/ParserTest.php b/tests/ParserTest.php
index da7cc549..217ecd16 100644
--- a/tests/ParserTest.php
+++ b/tests/ParserTest.php
@@ -2,6 +2,7 @@
 
 namespace Sabberworm\CSS\Tests;
 
+use PHPUnit\Framework\TestCase;
 use Sabberworm\CSS\CSSList\Document;
 use Sabberworm\CSS\CSSList\KeyFrame;
 use Sabberworm\CSS\Parser;
@@ -14,10 +15,11 @@
 use Sabberworm\CSS\RuleSet\AtRuleSet;
 use Sabberworm\CSS\RuleSet\DeclarationBlock;
 use Sabberworm\CSS\Settings;
+use Sabberworm\CSS\Value\Color;
 use Sabberworm\CSS\Value\Size;
 use Sabberworm\CSS\Value\URL;
 
-class ParserTest extends \PHPUnit\Framework\TestCase
+class ParserTest extends TestCase
 {
     public function testFiles()
     {
@@ -346,7 +348,7 @@ public function testRuleGetters()
         $this->assertSame('background-color', $aHeaderRules[1]->getRule());
         $aHeaderRules = $oHeaderBlock->getRulesAssoc('background-');
         $this->assertCount(1, $aHeaderRules);
-        $this->assertTrue($aHeaderRules['background-color']->getValue() instanceof \Sabberworm\CSS\Value\Color);
+        $this->assertTrue($aHeaderRules['background-color']->getValue() instanceof Color);
         $this->assertSame('rgba', $aHeaderRules['background-color']->getValue()->getColorDescription());
         $oHeaderBlock->removeRule($aHeaderRules['background-color']);
         $aHeaderRules = $oHeaderBlock->getRules('background-');
diff --git a/tests/RuleSet/DeclarationBlockTest.php b/tests/RuleSet/DeclarationBlockTest.php
index 1b2ce31c..31fe7f52 100644
--- a/tests/RuleSet/DeclarationBlockTest.php
+++ b/tests/RuleSet/DeclarationBlockTest.php
@@ -2,11 +2,12 @@
 
 namespace Sabberworm\CSS\Tests\RuleSet;
 
+use PHPUnit\Framework\TestCase;
 use Sabberworm\CSS\Parser;
 use Sabberworm\CSS\Rule\Rule;
 use Sabberworm\CSS\Value\Size;
 
-class DeclarationBlockTest extends \PHPUnit\Framework\TestCase
+class DeclarationBlockTest extends TestCase
 {
     /**
      * @dataProvider expandBorderShorthandProvider
diff --git a/tests/RuleSet/LenientParsingTest.php b/tests/RuleSet/LenientParsingTest.php
index 6b9095fe..f7530958 100644
--- a/tests/RuleSet/LenientParsingTest.php
+++ b/tests/RuleSet/LenientParsingTest.php
@@ -2,10 +2,11 @@
 
 namespace Sabberworm\CSS\Tests\RuleSet;
 
+use PHPUnit\Framework\TestCase;
 use Sabberworm\CSS\Parser;
 use Sabberworm\CSS\Settings;
 
-class LenientParsingTest extends \PHPUnit\Framework\TestCase
+class LenientParsingTest extends TestCase
 {
     /**
      * @expectedException \Sabberworm\CSS\Parsing\UnexpectedTokenException