diff --git a/src/Colors/Hsl/Decoders/StringColorDecoder.php b/src/Colors/Hsl/Decoders/StringColorDecoder.php
index 67ff03da..8ea7ed94 100644
--- a/src/Colors/Hsl/Decoders/StringColorDecoder.php
+++ b/src/Colors/Hsl/Decoders/StringColorDecoder.php
@@ -22,7 +22,7 @@ class StringColorDecoder extends AbstractDecoder implements DecoderInterface
             throw new DecoderException('Unable to decode input');
         }
 
-        $pattern = '/^hsl\((?P<h>[0-9\.]+), ?(?P<s>[0-9\.]+%?), ?(?P<l>[0-9\.]+%?)?\)$/i';
+        $pattern = '/^hsl\((?P<h>[0-9\.]+), ?(?P<s>[0-9\.]+%?), ?(?P<l>[0-9\.]+%?)\)$/i';
         if (preg_match($pattern, $input, $matches) != 1) {
             throw new DecoderException('Unable to decode input');
         }