diff --git a/apps/dav/lib/CalDAV/CalDavBackend.php b/apps/dav/lib/CalDAV/CalDavBackend.php
index 15dabdbb14..0a57ce1745 100644
--- a/apps/dav/lib/CalDAV/CalDavBackend.php
+++ b/apps/dav/lib/CalDAV/CalDavBackend.php
@@ -2678,7 +2678,7 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 					if (!$this->db->supports4ByteText()) {
 						$value = preg_replace('/[\x{10000}-\x{10FFFF}]/u', "\xEF\xBF\xBD", $value);
 					}
-					$value = mb_substr($value, 0, 254);
+					$value = mb_strcut($value, 0, 254);
 
 					$query->setParameter('name', $property->name);
 					$query->setParameter('parameter', null);
@@ -2698,8 +2698,8 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 							}
 
 							$query->setParameter('name', $property->name);
-							$query->setParameter('parameter', mb_substr($key, 0, 254));
-							$query->setParameter('value', mb_substr($value, 0, 254));
+							$query->setParameter('parameter', mb_strcut($key, 0, 254));
+							$query->setParameter('value', mb_strcut($value, 0, 254));
 							$query->executeUpdate();
 						}
 					}
diff --git a/apps/dav/lib/CardDAV/CardDavBackend.php b/apps/dav/lib/CardDAV/CardDavBackend.php
index 9246fc68ac..fa7db3750f 100644
--- a/apps/dav/lib/CardDAV/CardDavBackend.php
+++ b/apps/dav/lib/CardDAV/CardDavBackend.php
@@ -1271,7 +1271,7 @@ class CardDavBackend implements BackendInterface, SyncSupport {
 				}
 			}
 			$query->setParameter('name', $property->name);
-			$query->setParameter('value', mb_substr($property->getValue(), 0, 254));
+			$query->setParameter('value', mb_strcut($property->getValue(), 0, 254));
 			$query->setParameter('preferred', $preferred);
 			$query->execute();
 		}