diff --git a/core/profiles/demo_umami/demo_umami.install b/core/profiles/demo_umami/demo_umami.install
index 4137ca2ef37fbc50642a444711c01cdb404ac44d..5c0c94669a6a0a14986f84fedee6a2fba2c60e8f 100644
--- a/core/profiles/demo_umami/demo_umami.install
+++ b/core/profiles/demo_umami/demo_umami.install
@@ -35,8 +35,9 @@ function demo_umami_requirements($phase) {
  */
 function demo_umami_install() {
   // Assign user 1 the "administrator" role.
+  /** @var \Drupal\user\Entity\User $user */
   $user = User::load(1);
-  $user->roles[] = 'administrator';
+  $user->addRole('administrator');
   $user->save();
 
   // We install some menu links, so we have to rebuild the router, to ensure the
diff --git a/core/profiles/standard/standard.install b/core/profiles/standard/standard.install
index 990ca38d2c8a147ee7b5b0656397bea1e8d8230d..22bb1877bd5f6bf175364425757e40581cc44c8d 100644
--- a/core/profiles/standard/standard.install
+++ b/core/profiles/standard/standard.install
@@ -17,8 +17,9 @@
  */
 function standard_install() {
   // Assign user 1 the "administrator" role.
+  /** @var \Drupal\user\Entity\User $user */
   $user = User::load(1);
-  $user->roles[] = 'administrator';
+  $user->addRole('administrator');
   $user->save();
 
   // Populate the default shortcut set.