diff --git a/Inline.php b/Inline.php
index 77aa98ff..5a2db22a 100644
--- a/Inline.php
+++ b/Inline.php
@@ -716,8 +716,13 @@ private static function evaluateScalar(string $scalar, int $flags, array &$refer
                     case Parser::preg_match('/^(-|\+)?[0-9][0-9_]*(\.[0-9_]+)?$/', $scalar):
                         return (float) str_replace('_', '', $scalar);
                     case Parser::preg_match(self::getTimestampRegex(), $scalar):
-                        // When no timezone is provided in the parsed date, YAML spec says we must assume UTC.
-                        $time = new \DateTimeImmutable($scalar, new \DateTimeZone('UTC'));
+                        try {
+                            // When no timezone is provided in the parsed date, YAML spec says we must assume UTC.
+                            $time = new \DateTimeImmutable($scalar, new \DateTimeZone('UTC'));
+                        } catch (\Exception $e) {
+                            // Some dates accepted by the regex are not valid dates
+                            return (string) $scalar;
+                        }
 
                         if (Yaml::PARSE_DATETIME & $flags) {
                             return $time;