diff --git a/src/CSSList/CSSList.php b/src/CSSList/CSSList.php
index 84ece7f8..f18cd772 100644
--- a/src/CSSList/CSSList.php
+++ b/src/CSSList/CSSList.php
@@ -72,9 +72,15 @@ public static function parseList(ParserState $parserState, CSSList $list): void
             $listItem = null;
             if ($usesLenientParsing) {
                 try {
+                    $positionBeforeParse = $parserState->currentColumn();
                     $listItem = self::parseListItem($parserState, $list);
                 } catch (UnexpectedTokenException $e) {
                     $listItem = false;
+                    // If the failed parsing did not consume anything that was to come ...
+                    if ($parserState->currentColumn() === $positionBeforeParse && !$parserState->isEnd()) {
+                        // ... the unexpected token needs to be skipped, otherwise there'll be an infinite loop.
+                        $parserState->consume(1);
+                    }
                 }
             } else {
                 $listItem = self::parseListItem($parserState, $list);
diff --git a/src/Parsing/ParserState.php b/src/Parsing/ParserState.php
index df825377..44f96a94 100644
--- a/src/Parsing/ParserState.php
+++ b/src/Parsing/ParserState.php
@@ -192,6 +192,10 @@ public function parseCharacter(bool $isForIdentifier): ?string
      *
      * @throws UnexpectedEOFException
      * @throws UnexpectedTokenException
+     *
+     * @phpstan-impure
+     * This method may change the state of the object by advancing the internal position;
+     * it does not simply 'get' a value.
      */
     public function consumeWhiteSpace(): array
     {