diff --git a/src/Fixer/LanguageConstruct/ClassKeywordFixer.php b/src/Fixer/LanguageConstruct/ClassKeywordFixer.php
new file mode 100644
index 00000000000..a227f2efd9f
--- /dev/null
+++ b/src/Fixer/LanguageConstruct/ClassKeywordFixer.php
@@ -0,0 +1,96 @@
+<?php
+
+/*
+ * This file is part of PHP CS Fixer.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *     Dariusz Rumiński <dariusz.ruminski@gmail.com>
+ *
+ * This source file is subject to the MIT license that is bundled
+ * with this source code in the file LICENSE.
+ */
+
+namespace PhpCsFixer\Fixer\LanguageConstruct;
+
+use PhpCsFixer\AbstractFixer;
+use PhpCsFixer\FixerDefinition\FixerDefinition;
+use PhpCsFixer\FixerDefinition\VersionSpecification;
+use PhpCsFixer\FixerDefinition\VersionSpecificCodeSample;
+use PhpCsFixer\Tokenizer\CT;
+use PhpCsFixer\Tokenizer\Token;
+use PhpCsFixer\Tokenizer\Tokens;
+use PhpCsFixer\Tokenizer\TokensAnalyzer;
+use PhpCsFixer\Indicator\ClassyExistanceIndicator;
+
+/**
+ * @author Dariusz Rumiński <dariusz.ruminski@gmail.com>
+ */
+final class ClassKeywordFixer extends AbstractFixer
+{
+    /**
+     * @var string[]
+     */
+    private $imports = array();
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getDefinition()
+    {
+        return new FixerDefinition(
+            'Converts FQCN strings to `*::class` keywords. Requires PHP >= 5.5.',
+            array(
+                new VersionSpecificCodeSample(
+                    '<?php
+
+use Foo\Bar\Baz;
+
+$className = Baz::class;
+',
+                    new VersionSpecification(50500)
+                ),
+            )
+        );
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function isCandidate(Tokens $tokens)
+    {
+        return PHP_VERSION_ID >= 50500;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function applyFix(\SplFileInfo $file, Tokens $tokens)
+    {
+        $indicator = new ClassyExistanceIndicator();
+
+        for ($index = $tokens->count() - 1; $index >= 0; --$index) {
+            $token = $tokens[$index];
+
+            if ($token->isGivenKind(T_CONSTANT_ENCAPSED_STRING)) {
+                $name = substr($token->getContent(), 1, -1);
+                $name = ltrim($name, '\\');
+                $name = str_replace('\\\\', '\\', $name);
+
+                if ($indicator->exists($name)) {
+                    try {
+                        $substitution = Tokens::fromCode("<?php echo \\$name::class;");
+                        $substitution->clearRange(0, 2);
+                        $substitution[$substitution->getSize() - 1]->clear();
+                        $substitution->clearEmptyTokens();
+
+                        $token->clear();
+                        $tokens->insertAt($index, $substitution);
+                    } catch (\Error $e) {
+                        var_dump("error with parsing class", $name);
+                        var_dump($e->getMessage());
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/src/Indicator/ClassyExistanceIndicator.php b/src/Indicator/ClassyExistanceIndicator.php
new file mode 100644
index 00000000000..863049b5f4c
--- /dev/null
+++ b/src/Indicator/ClassyExistanceIndicator.php
@@ -0,0 +1,35 @@
+<?php
+
+/*
+ * This file is part of PHP CS Fixer.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *     Dariusz Rumiński <dariusz.ruminski@gmail.com>
+ *
+ * This source file is subject to the MIT license that is bundled
+ * with this source code in the file LICENSE.
+ */
+
+namespace PhpCsFixer\Indicator;
+
+/**
+ * @internal
+ */
+final class ClassyExistanceIndicator
+{
+    /**
+     * @param string $name
+     *
+     * @return bool
+     */
+    public function exists($name)
+    {
+        if (class_exists($name) || interface_exists($name) || trait_exists($name)) {
+            $rc = new \ReflectionClass($name);
+
+            return $rc->getName() === $name;
+        }
+
+        return false;
+    }
+}