diff --git a/backend/bin/seed.ts b/backend/bin/seed.ts
index a0b568f75..fa7da4fe2 100644
--- a/backend/bin/seed.ts
+++ b/backend/bin/seed.ts
@@ -406,7 +406,7 @@ const seed = async () => {
         photo: undefined,
         teacher_in_charge_name: "",
         teacher_in_charge_email: "",
-        start_date: "",
+        start_date: undefined,
         status: course.status as CourseStatus,
         course_translations: course.course_translations
           ? {
diff --git a/frontend/components/NewLayout/Navigation/DesktopNavigationMenu.tsx b/frontend/components/NewLayout/Navigation/DesktopNavigationMenu.tsx
index 3be557415..9969857cd 100644
--- a/frontend/components/NewLayout/Navigation/DesktopNavigationMenu.tsx
+++ b/frontend/components/NewLayout/Navigation/DesktopNavigationMenu.tsx
@@ -90,8 +90,10 @@ const UserOptionsMenu = () => {
           label: t("loginShort"),
         },
         {
-          href: "/sign-up",
+          href: "https://courses.mooc.fi/signup",
           label: t("signUp"),
+          target: "_blank",
+          rel: "noopener noreferrer",
         },
       ]}
     />
diff --git a/frontend/components/NewLayout/Navigation/MobileNavigationMenu.tsx b/frontend/components/NewLayout/Navigation/MobileNavigationMenu.tsx
index 7e06dba2a..a7d91e4a1 100644
--- a/frontend/components/NewLayout/Navigation/MobileNavigationMenu.tsx
+++ b/frontend/components/NewLayout/Navigation/MobileNavigationMenu.tsx
@@ -357,7 +357,7 @@ const MobileMenuItem = ({ item, level = 0 }: MobileMenuItemProps) => {
   const { pathname } = useRouter()
 
   const hasSubmenu = isSubmenuItem(item)
-  const { href, label, onClick } = item
+  const { href, label, onClick, target, rel } = item
   const onItemClick = useEventCallback(() => {
     setBreadcrumbs((prev) => [...prev, item])
     setCurrentLevel(level + 1)
@@ -373,6 +373,8 @@ const MobileMenuItem = ({ item, level = 0 }: MobileMenuItemProps) => {
         variant="text"
         href={href}
         onClick={onClick ? onClick : undefined}
+        target={target}
+        rel={rel}
       >
         {level > 0 && <CaretRightIcon sx={{ fontSize: 10 }} />}
         <span>{label}</span>
@@ -517,8 +519,10 @@ const MobileNavigationMenu = ({
               label: t("loginShort"),
             },
             {
-              href: "/sign-up",
+              href: "https://courses.mooc.fi/signup",
               label: t("signUp"),
+              target: "_blank",
+              rel: "noopener noreferrer",
             },
           ]),
     ],
diff --git a/frontend/components/NewLayout/Navigation/NavigationLinks.tsx b/frontend/components/NewLayout/Navigation/NavigationLinks.tsx
index 4fb91cdb8..a0e4d753c 100644
--- a/frontend/components/NewLayout/Navigation/NavigationLinks.tsx
+++ b/frontend/components/NewLayout/Navigation/NavigationLinks.tsx
@@ -56,13 +56,13 @@ interface NavigationItemProps {
 }
 
 const NavigationItem = ({ item }: NavigationItemProps) => {
-  const { name, label, href, onClick } = item
+  const { name, label, href, onClick, target, rel } = item
   return (
     <NavigationLinkItem key={name ?? label}>
       {isSubmenuItem(item) ? (
         <NavigationDropdownLink item={item} />
       ) : (
-        <NavigationLink href={href} onClick={onClick}>
+        <NavigationLink href={href} onClick={onClick} target={target} rel={rel}>
           {label}
         </NavigationLink>
       )}
diff --git a/frontend/components/NewLayout/Navigation/index.tsx b/frontend/components/NewLayout/Navigation/index.tsx
index e2f0a9f71..03eff02b9 100644
--- a/frontend/components/NewLayout/Navigation/index.tsx
+++ b/frontend/components/NewLayout/Navigation/index.tsx
@@ -45,6 +45,8 @@ export type NavigationMenuLinkItem = {
   name?: string
   description?: string
   onClick?: (...params: any[]) => any
+  target?: string
+  rel?: string
 }
 
 export type NavigationMenuShortcutItem = {