diff --git a/lib/Sabberworm/CSS/CSSList/CSSList.php b/lib/Sabberworm/CSS/CSSList/CSSList.php
index 3736d8f3..d883df82 100644
--- a/lib/Sabberworm/CSS/CSSList/CSSList.php
+++ b/lib/Sabberworm/CSS/CSSList/CSSList.php
@@ -142,6 +142,13 @@ private static function parseAtRule(ParserState $oParserState) {
 		} else {
 			//Unknown other at rule (font-face or such)
 			$sArgs = trim($oParserState->consumeUntil('{', false, true));
+			if (substr_count($sArgs, "(") != substr_count($sArgs, ")")) {
+				if($oParserState->getSettings()->bLenientParsing) {
+					return NULL;
+				} else {
+					throw new SourceException("Unmatched brace count in media query", $oParserState->currentLine());
+				}
+			}
 			$bUseRuleSet = true;
 			foreach(explode('/', AtRule::BLOCK_RULES) as $sBlockRuleName) {
 				if(self::identifierIs($sIdentifier, $sBlockRuleName)) {
diff --git a/tests/Sabberworm/CSS/ParserTest.php b/tests/Sabberworm/CSS/ParserTest.php
index 0922b11e..0bee410c 100644
--- a/tests/Sabberworm/CSS/ParserTest.php
+++ b/tests/Sabberworm/CSS/ParserTest.php
@@ -420,6 +420,12 @@ function testEmptyGridLineNameLenientInFile() {
 		$this->assertSame($sExpected, $oDoc->render());
 	}
 
+	function testUnmatchedBracesInFile() {
+		$oDoc = $this->parsedStructureForFile('unmatched_braces', Settings::create()->withMultibyteSupport(true));
+		$sExpected = 'button, input, checkbox, textarea {outline: 0;margin: 0;}';
+		$this->assertSame($sExpected, $oDoc->render());
+	}
+
 	/**
 	* @expectedException Sabberworm\CSS\Parsing\UnexpectedTokenException
 	*/
diff --git a/tests/files/unmatched_braces.css b/tests/files/unmatched_braces.css
new file mode 100644
index 00000000..b7172762
--- /dev/null
+++ b/tests/files/unmatched_braces.css
@@ -0,0 +1,18 @@
+button,input,checkbox,textarea {
+    outline: 0;
+    margin: 0;
+}
+
+@media only screen and (-webkit-min-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio:3/@media all and (orientation:portrait) {
+    #wrapper {
+        max-width:640px;
+        margin: 0 auto;
+    }
+}
+
+@media all and (orientation: landscape) {
+    #wrapper {
+        max-width:640px;
+        margin: 0 auto;
+    }
+}