diff --git a/typo3/sysext/redirects/Classes/Service/RedirectService.php b/typo3/sysext/redirects/Classes/Service/RedirectService.php
index 7a450343a57c293164db0aacd31dba37f6beaca1..70ba13a425668e14a736135d631ab981d89b1312 100644
--- a/typo3/sysext/redirects/Classes/Service/RedirectService.php
+++ b/typo3/sysext/redirects/Classes/Service/RedirectService.php
@@ -212,7 +212,7 @@ class RedirectService implements LoggerAwareInterface
         }
         // Do this for files, folders, external URLs
         if (!empty($linkDetails['url'])) {
-            if ($matchedRedirect['is_regexp']) {
+            if ($matchedRedirect['is_regexp'] ?? false) {
                 $linkDetails = $this->replaceRegExpCaptureGroup($matchedRedirect, $uri, $linkDetails);
             }