diff --git a/client/src/components/time-ticket-modal/time-ticket-modal.component.jsx b/client/src/components/time-ticket-modal/time-ticket-modal.component.jsx
index 83087d374..4774c6810 100644
--- a/client/src/components/time-ticket-modal/time-ticket-modal.component.jsx
+++ b/client/src/components/time-ticket-modal/time-ticket-modal.component.jsx
@@ -237,7 +237,7 @@ export function TimeTicketModalComponent({
                       return Promise.reject(
                         t("timetickets.validation.clockoffwithoutclockon")
                       );
-                    if (!value.isSameOrAfter(clockon))
+                    if (value && !value.isSameOrAfter(clockon))
                       return Promise.reject(
                         t("timetickets.validation.clockoffmustbeafterclockon")
                       );