diff --git a/lib/cucumber/rails/hooks/mail.rb b/lib/cucumber/rails/hooks/mail.rb
index a65898cc..85761ce9 100644
--- a/lib/cucumber/rails/hooks/mail.rb
+++ b/lib/cucumber/rails/hooks/mail.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
-Before do
-  ActionMailer::Base.deliveries = []
+if defined?(::ActionMailer)
+  Before do
+    ActionMailer::Base.deliveries = []
+  end
 end