diff --git a/lib/php-css-parser/CSSList/CSSBlockList.php b/lib/php-css-parser/CSSList/CSSBlockList.php
index 17c68142eb7..15742423deb 100644
--- a/lib/php-css-parser/CSSList/CSSBlockList.php
+++ b/lib/php-css-parser/CSSList/CSSBlockList.php
@@ -69,9 +69,34 @@ abstract class CSSBlockList extends CSSList {
 				if ($sSpecificitySearch === null) {
 					$aResult[] = $oSelector;
 				} else {
-					$sComparison = "\$bRes = {$oSelector->getSpecificity()} $sSpecificitySearch;";
-					eval($sComparison);
-					if ($bRes) {
+					$sComparator = '===';
+					$aSpecificitySearch = explode(' ', $sSpecificitySearch);
+					$iTargetSpecificity = $aSpecificitySearch[0];
+					if(count($aSpecificitySearch) > 1) {
+						$sComparator = $aSpecificitySearch[0];
+						$iTargetSpecificity = $aSpecificitySearch[1];
+					}
+					$iTargetSpecificity = (int)$iTargetSpecificity;
+					$iSelectorSpecificity = $oSelector->getSpecificity();
+					$bMatches = false;
+					switch($sComparator) {
+						case '<=':
+							$bMatches = $iSelectorSpecificity <= $iTargetSpecificity;
+						break;
+						case '<':
+							$bMatches = $iSelectorSpecificity < $iTargetSpecificity;
+						break;
+						case '>=':
+							$bMatches = $iSelectorSpecificity >= $iTargetSpecificity;
+						break;
+						case '>':
+							$bMatches = $iSelectorSpecificity > $iTargetSpecificity;
+						break;
+						default:
+							$bMatches = $iSelectorSpecificity === $iTargetSpecificity;
+						break;
+					}
+					if ($bMatches) {
 						$aResult[] = $oSelector;
 					}
 				}
diff --git a/lib/php-css-parser/CSSList/Document.php b/lib/php-css-parser/CSSList/Document.php
index 873df755f7f..1658aee8dbb 100644
--- a/lib/php-css-parser/CSSList/Document.php
+++ b/lib/php-css-parser/CSSList/Document.php
@@ -72,9 +72,6 @@ class Document extends CSSBlockList {
 	 * @example getSelectorsBySpecificity('>= 100')
 	 */
 	public function getSelectorsBySpecificity($sSpecificitySearch = null) {
-		if (is_numeric($sSpecificitySearch) || is_numeric($sSpecificitySearch[0])) {
-			$sSpecificitySearch = "== $sSpecificitySearch";
-		}
 		$aResult = array();
 		$this->allSelectors($aResult, $sSpecificitySearch);
 		return $aResult;
diff --git a/lib/php-css-parser/moodle_readme.txt b/lib/php-css-parser/moodle_readme.txt
index 07f3b4d33ed..4040005a941 100644
--- a/lib/php-css-parser/moodle_readme.txt
+++ b/lib/php-css-parser/moodle_readme.txt
@@ -1,12 +1,9 @@
 PHP CSS Parser
 --------------
 
-Downloaded from: https://github.com/sabberworm/PHP-CSS-Parser/releases/tag/8.3.0
-
 Import procedure:
-
-- Copy all the files from the folder 'lib/Sabberworm/CSS/' in this directory.
-
-- Apply the patch in Sabberworm/PHP-CSS-Parser#115
-
-- Apply the patch in sabberworm/PHP-CSS-Parser/issues/173 (if this has not already been resolved upstream).
+1. Download the latest release from https://github.com/sabberworm/PHP-CSS-Parser/releases
+2. Copy all the files from the folder 'lib/Sabberworm/CSS/' in this directory.
+3. Apply the following patches from the following pull requests if they have not yet been merged upstream:
+   a. https://github.com/sabberworm/PHP-CSS-Parser/pull/115
+   b. https://github.com/sabberworm/PHP-CSS-Parser/pull/173
diff --git a/lib/thirdpartylibs.xml b/lib/thirdpartylibs.xml
index 226f8bce18a..15a443f114f 100644
--- a/lib/thirdpartylibs.xml
+++ b/lib/thirdpartylibs.xml
@@ -217,7 +217,7 @@
     <location>php-css-parser</location>
     <name>PHP-CSS-Parser</name>
     <license>MIT</license>
-    <version>8.3.0</version>
+    <version>8.3.1</version>
   </library>
   <library>
     <location>rtlcss</location>