diff --git a/class.csstidy.php b/class.csstidy.php
index 4fa5226..d15c585 100644
--- a/class.csstidy.php
+++ b/class.csstidy.php
@@ -70,7 +70,7 @@
  * An online version should be available here: http://cdburnerxp.se/cssparse/css_optimiser.php
  * @package csstidy
  * @author Florian Schmitz (floele at gmail dot com) 2005-2006
- * @version 2.2.0
+ * @version 2.2.1
  */
 class csstidy {
 
diff --git a/data.inc.php b/data.inc.php
index 8e1a3aa..11ff043 100644
--- a/data.inc.php
+++ b/data.inc.php
@@ -55,7 +55,7 @@
  * @global array $data['csstidy']['at_rules']
  * @version 1.1
  */
-$data['csstidy']['at_rules'] = array('page' => 'is','font-face' => 'atis','charset' => 'iv', 'import' => 'iv','namespace' => 'iv','media' => 'at', 'supports' => 'at', 'keyframes' => 'at','-moz-keyframes' => 'at','-o-keyframes' => 'at','-webkit-keyframes' => 'at','-ms-keyframes' => 'at');
+$data['csstidy']['at_rules'] = array('page' => 'is','font-face' => 'atis','charset' => 'iv', 'import' => 'iv','namespace' => 'iv','media' => 'at', 'supports' => 'at', 'keyframes' => 'at','-moz-keyframes' => 'at','-o-keyframes' => 'at','-webkit-keyframes' => 'at','-ms-keyframes' => 'at','container' => 'at');
 
  /**
  * Properties that need a value with unit
@@ -647,4 +647,4 @@
 $data['csstidy']['predefined_templates']['low_compression'][] = '	';
 $data['csstidy']['predefined_templates']['low_compression'][] = '<span class="comment">'; // before comment
 $data['csstidy']['predefined_templates']['low_compression'][] = '</span>'."\n"; // after comment
-$data['csstidy']['predefined_templates']['low_compression'][] = "\n";
+$data['csstidy']['predefined_templates']['low_compression'][] = "\n";
\ No newline at end of file
diff --git a/tests/Fixtures/special/container.css b/tests/Fixtures/special/container.css
new file mode 100644
index 0000000..de5d9dc
--- /dev/null
+++ b/tests/Fixtures/special/container.css
@@ -0,0 +1,5 @@
+@container myContainer (width < 500px) {
+  .child {
+    width: 50%;
+  }
+}
\ No newline at end of file
diff --git a/tests/Fixtures/special/container.full-expected.php b/tests/Fixtures/special/container.full-expected.php
new file mode 100644
index 0000000..565118c
--- /dev/null
+++ b/tests/Fixtures/special/container.full-expected.php
@@ -0,0 +1,9 @@
+<?php
+
+return array (
+	'@container myContainer (width 500px) ' => array(
+		'.child' => array(
+			'width' => '50%',
+		)
+	)
+);
\ No newline at end of file
diff --git a/tests/Fixtures/special/container.php b/tests/Fixtures/special/container.php
new file mode 100644
index 0000000..bd5b05f
--- /dev/null
+++ b/tests/Fixtures/special/container.php
@@ -0,0 +1,6 @@
+<?php
+
+return [
+	'test' => '@container',
+	'settings' => [],
+];
\ No newline at end of file