diff --git a/lib/job-iteration/iteration.rb b/lib/job-iteration/iteration.rb
index 11edf7bd..d6835209 100644
--- a/lib/job-iteration/iteration.rb
+++ b/lib/job-iteration/iteration.rb
@@ -40,7 +40,7 @@ def inspected_cursor
       end
     end
 
-    included do |_base|
+    included do |base|
       define_callbacks :start
       define_callbacks :shutdown
       define_callbacks :complete
@@ -49,10 +49,16 @@ def inspected_cursor
         :job_iteration_max_job_runtime,
         instance_writer: false,
         instance_predicate: false,
-        default: JobIteration.max_job_runtime,
       )
 
-      singleton_class.prepend(PrependedClassMethods)
+      class << base
+        prepend(PrependedClassMethods)
+
+        def job_iteration_max_job_runtime
+          # Lookup default every time, instead of closing around its value when the class is defined.
+          JobIteration.max_job_runtime
+        end
+      end
     end
 
     module PrependedClassMethods
diff --git a/test/unit/iteration_test.rb b/test/unit/iteration_test.rb
index 642b1f8c..85787d88 100644
--- a/test/unit/iteration_test.rb
+++ b/test/unit/iteration_test.rb
@@ -311,6 +311,17 @@ def test_global_max_job_runtime
     end
   end
 
+  def test_global_max_job_runtime_with_updated_value
+    freeze_time
+    with_global_max_job_runtime(10.minutes) do
+      klass = build_slow_job_class(iterations: 3, iteration_duration: 30.seconds)
+      with_global_max_job_runtime(1.minute) do
+        klass.perform_now
+        assert_partially_completed_job(cursor_position: 2)
+      end
+    end
+  end
+
   def test_per_class_max_job_runtime_with_default_global
     freeze_time
     parent = build_slow_job_class(iterations: 3, iteration_duration: 30.seconds)