diff --git a/.gitattributes b/.gitattributes
index 6b8e4eea1e9..944be372e46 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,31 +1,26 @@
 # @TODO 3.0 replace following `tests/... export-ignore` with single `tests/ export-ignore`
-tests/**/*Test.php export-ignore
-tests/AbstractDoctrineAnnotationFixerTestCase.php export-ignore
-tests/Differ/AbstractDifferTestCase.php export-ignore
-tests/Fixtures/ export-ignore
-tests/Linter/AbstractLinterTestCase.php export-ignore
-tests/Report/AbstractReporterTestCase.php export-ignore
-tests/Test/AbstractFixerWithAliasedOptionsTestCase.php export-ignore
-tests/Test/AbstractTransformerTestCase.php export-ignore
+/tests/**/*Test.php export-ignore
+/tests/AbstractDoctrineAnnotationFixerTestCase.php export-ignore
+/tests/Differ/AbstractDifferTestCase.php export-ignore
+/tests/Fixtures/ export-ignore
+/tests/Linter/AbstractLinterTestCase.php export-ignore
+/tests/Report/AbstractReporterTestCase.php export-ignore
+/tests/Test/AbstractFixerWithAliasedOptionsTestCase.php export-ignore
+/tests/Test/AbstractTransformerTestCase.php export-ignore
 
-.appveyor.yml export-ignore
-.circleci/ export-ignore
-.composer-require-checker.json export-ignore
-.editorconfig export-ignore
-.gitattributes export-ignore
-.github/ export-ignore
-.gitignore export-ignore
-.travis.yml export-ignore
-benchmark.sh export-ignore
-box.json export-ignore
-check_trailing_spaces.sh export-ignore
-phpmd.xml export-ignore
-phpunit.xml.dist export-ignore
+/.* export-ignore
+/benchmark.sh export-ignore
+/box.json.dist export-ignore
+/check_trailing_spaces.sh export-ignore
+/dev-tools/ export-ignore
+/phpmd.xml export-ignore
+/phpstan.neon export-ignore
+/phpunit.xml.dist export-ignore
 
 *       text=auto eol=lf
-*.php   text whitespace=blank-at-eol,blank-at-eof,space-before-tab,tab-in-indent,tabwidth=4 diff=php
 *.json  text whitespace=blank-at-eol,blank-at-eof,space-before-tab,tab-in-indent,tabwidth=4
-*.yml   text whitespace=blank-at-eol,blank-at-eof,space-before-tab,tab-in-indent,tabwidth=4
 *.md    text whitespace=blank-at-eol,blank-at-eof
+*.php   text whitespace=blank-at-eol,blank-at-eof,space-before-tab,tab-in-indent,tabwidth=4 diff=php
 *.rst   text whitespace=blank-at-eol,blank-at-eof
-tests/Fixtures/**/* -text
+*.yml   text whitespace=blank-at-eol,blank-at-eof,space-before-tab,tab-in-indent,tabwidth=4
+/tests/Fixtures/**/* -text
diff --git a/box.json.dist b/box.json.dist
index f9867a6fe06..e4102debea2 100644
--- a/box.json.dist
+++ b/box.json.dist
@@ -7,7 +7,7 @@
         "KevinGH\\Box\\Compactor\\Php"
     ],
     "files": [
-        "dev-tools/ci-integration.sh",
+        "ci-integration.sh",
         "LICENSE"
     ],
     "finder": [
diff --git a/dev-tools/ci-integration.sh b/ci-integration.sh
similarity index 100%
rename from dev-tools/ci-integration.sh
rename to ci-integration.sh
diff --git a/php-cs-fixer b/php-cs-fixer
index b8cd9fef879..1fec90ca11d 100755
--- a/php-cs-fixer
+++ b/php-cs-fixer
@@ -37,6 +37,19 @@ if (defined('HHVM_VERSION_ID')) {
     }
 }
 
+foreach (['json', 'tokenizer'] as $extension) {
+    if (!extension_loaded($extension)) {
+        fwrite(STDERR, sprintf("PHP extension ext-%s is missing from your system. Install or enable it.\n", $extension));
+
+        if (getenv('PHP_CS_FIXER_IGNORE_ENV')) {
+            fwrite(STDERR, "Ignoring environment requirements because `PHP_CS_FIXER_IGNORE_ENV` is set. Execution may be unstable.\n");
+        } else {
+            exit(1);
+        }
+    }
+}
+unset($extension);
+
 set_error_handler(function ($severity, $message, $file, $line) {
     if ($severity & error_reporting()) {
         throw new ErrorException($message, 0, $severity, $file, $line);
diff --git a/src/Console/Command/HelpCommand.php b/src/Console/Command/HelpCommand.php
index 9633f2dad3b..06e605b1f23 100644
--- a/src/Console/Command/HelpCommand.php
+++ b/src/Console/Command/HelpCommand.php
@@ -285,7 +285,7 @@ public static function getHelpCopy()
             ),
             '%%%CI_INTEGRATION%%%' => implode("\n", array_map(
                 static function ($line) { return '    $ '.$line; },
-                \array_slice(file(__DIR__.'/../../../dev-tools/ci-integration.sh', FILE_IGNORE_NEW_LINES), 3)
+                \array_slice(file(__DIR__.'/../../../ci-integration.sh', FILE_IGNORE_NEW_LINES), 3)
             )),
             '%%%FIXERS_DETAILS%%%' => self::getFixersHelp(),
         ]);
diff --git a/tests/Smoke/CiIntegrationTest.php b/tests/Smoke/CiIntegrationTest.php
index 7413a2ffe9f..63f54ccde9e 100644
--- a/tests/Smoke/CiIntegrationTest.php
+++ b/tests/Smoke/CiIntegrationTest.php
@@ -103,7 +103,7 @@ public function testIntegration(
             $caseCommands
         ));
 
-        $integrationScript = explode("\n", str_replace('vendor/bin/', './../../../', file_get_contents(__DIR__.'/../../dev-tools/ci-integration.sh')));
+        $integrationScript = explode("\n", str_replace('vendor/bin/', './../../../', file_get_contents(__DIR__.'/../../ci-integration.sh')));
         $steps = [
             "COMMIT_RANGE=\"master..{$branchName}\"",
             "{$integrationScript[3]}\n{$integrationScript[4]}",