diff --git a/lib/classes/hub/registration.php b/lib/classes/hub/registration.php
index b4f781c7be5..73a2378dc9e 100644
--- a/lib/classes/hub/registration.php
+++ b/lib/classes/hub/registration.php
@@ -578,7 +578,7 @@ class registration {
     }
 
     /**
-     * Redirect to the site registration form if it's a new install or registration needs updating
+     * Redirect to the site registration form if it's a new install, upgrade or registration needs updating.
      *
      * @param string|moodle_url $url
      */
diff --git a/lib/upgradelib.php b/lib/upgradelib.php
index cb70762d4a7..46b33f5bf7d 100644
--- a/lib/upgradelib.php
+++ b/lib/upgradelib.php
@@ -1921,6 +1921,9 @@ function upgrade_core($version, $verbose) {
         $syscontext->mark_dirty();
         core_upgrade_time::record_detail('context_system::mark_dirty');
 
+        // Prompt admin to register site. Reminder flow handles sites already registered, so admin won't be prompted if registered.
+        set_config('registrationpending', true);
+
         print_upgrade_part_end('moodle', false, $verbose);
     } catch (Exception $ex) {
         upgrade_handle_exception($ex);