diff --git a/db/migrate/20230223142119_set_default_public_user_role_on_protocols.rb b/db/migrate/20230223142119_set_default_public_user_role_on_protocols.rb
new file mode 100644
index 000000000..df9a1b3b2
--- /dev/null
+++ b/db/migrate/20230223142119_set_default_public_user_role_on_protocols.rb
@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class SetDefaultPublicUserRoleOnProtocols < ActiveRecord::Migration[6.1]
+  def change
+    Protocol.where(default_public_user_role_id: nil, visibility: :visible).update_all(
+      default_public_user_role_id: UserRole.find_predefined_viewer_role.id
+    )
+  end
+end