diff --git a/activejob/lib/active_job/queue_adapters/queue_classic_adapter.rb b/activejob/lib/active_job/queue_adapters/queue_classic_adapter.rb
index 1a46f20420..34c11a68b2 100644
--- a/activejob/lib/active_job/queue_adapters/queue_classic_adapter.rb
+++ b/activejob/lib/active_job/queue_adapters/queue_classic_adapter.rb
@@ -26,7 +26,7 @@ module ActiveJob
           queue = build_queue(job.queue_name)
           unless queue.respond_to?(:enqueue_at)
             raise NotImplementedError, 'To be able to schedule jobs with queue_classic ' \
-              'the QC::Queue needs to respond to `enqueue_at(timestamp, method, *args)`. '
+              'the QC::Queue needs to respond to `enqueue_at(timestamp, method, *args)`. ' \
               'You can implement this yourself or you can use the queue_classic-later gem.'
           end
           queue.enqueue_at(timestamp, "#{JobWrapper.name}.perform", job.serialize)