diff --git a/app/controllers/application_controller/with_university.rb b/app/controllers/application_controller/with_university.rb
index 8e9b06f0b33fbc5b70820edc901947526031f329..6fa37e2878780bede8d647ca08200a701b0ea6a1 100644
--- a/app/controllers/application_controller/with_university.rb
+++ b/app/controllers/application_controller/with_university.rb
@@ -2,6 +2,7 @@ module ApplicationController::WithUniversity
   extend ActiveSupport::Concern
 
   included do
+    # Raises ActiveRecord::RecordNotFound to prevent access from non-listed hosts
     def current_university
       @current_university ||= University.with_host(request.host)
     end
diff --git a/app/models/university/with_identifier.rb b/app/models/university/with_identifier.rb
index 5ed1c31a663cb43c418d6bcd82932a35e695c559..f11d17f1aa274493d15a5e27c5934b0f14702aca 100644
--- a/app/models/university/with_identifier.rb
+++ b/app/models/university/with_identifier.rb
@@ -14,7 +14,7 @@ module University::WithIdentifier
     end
 
     def self.with_host(host)
-      find_by(identifier: extract_identifier_from(host))
+      find_by!(identifier: extract_identifier_from(host))
     end
 
     private