diff --git a/app/models/good_job/base_execution.rb b/app/models/good_job/base_execution.rb
index 0120795e..51fc8876 100644
--- a/app/models/good_job/base_execution.rb
+++ b/app/models/good_job/base_execution.rb
@@ -602,7 +602,7 @@ def perform(lock_id:)
         job_attributes[:finished_at] = job_finished_at
         if discrete_execution
           discrete_execution.finished_at = job_finished_at
-          discrete_execution.duration = monotonic_duration if GoodJob::DiscreteExecution.monotonic_duration_migrated?
+          discrete_execution.duration = monotonic_duration if GoodJob::DiscreteExecution.monotonic_duration_migrated? && Gem::Version.new(Rails.version) >= Gem::Version.new('6.1.0.a')
         end
 
         retry_unhandled_error = result.unhandled_error && GoodJob.retry_on_unhandled_error
diff --git a/app/models/good_job/discrete_execution.rb b/app/models/good_job/discrete_execution.rb
index 7f2e0097..56654bd2 100644
--- a/app/models/good_job/discrete_execution.rb
+++ b/app/models/good_job/discrete_execution.rb
@@ -46,7 +46,8 @@ def queue_latency
 
     # Monotonic time between when this job started and finished
     def runtime_latency
-      if self.class.monotonic_duration_migrated?
+      # migrated and Rails greater than 6.1
+      if self.class.monotonic_duration_migrated? && Gem::Version.new(Rails.version) >= Gem::Version.new('6.1.0.a')
         duration
       elsif performed_at
         (finished_at || Time.current) - performed_at
diff --git a/spec/app/models/good_job/execution_spec.rb b/spec/app/models/good_job/execution_spec.rb
index 80d706d2..9853156c 100644
--- a/spec/app/models/good_job/execution_spec.rb
+++ b/spec/app/models/good_job/execution_spec.rb
@@ -702,7 +702,7 @@ def job_params
           created_at: within(0.001).of(good_job.performed_at),
           scheduled_at: within(0.001).of(good_job.created_at),
           finished_at: within(1.second).of(Time.current),
-          duration: be_present,
+          duration: Gem::Version.new(Rails.version) >= Gem::Version.new('6.1.0.a') ? be_present : nil,
           error: nil,
           serialized_params: good_job.serialized_params
         )
@@ -741,7 +741,7 @@ def job_params
             created_at: within(1.second).of(Time.current),
             scheduled_at: within(1.second).of(Time.current),
             finished_at: within(1.second).of(Time.current),
-            duration: be_present
+            duration: Gem::Version.new(Rails.version) >= Gem::Version.new('6.1.0.a') ? be_present : nil
           )
         end
       end
@@ -766,7 +766,7 @@ def job_params
           expect(good_job.discrete_executions.first).to have_attributes(
             performed_at: within(1.second).of(Time.current),
             finished_at: within(1.second).of(Time.current),
-            duration: be_present
+            duration: Gem::Version.new(Rails.version) >= Gem::Version.new('6.1.0.a') ? be_present : nil
           )
         end
       end
diff --git a/spec/lib/good_job/active_job_extensions/interrupt_errors_spec.rb b/spec/lib/good_job/active_job_extensions/interrupt_errors_spec.rb
index 2bd692a3..ad92cbf3 100644
--- a/spec/lib/good_job/active_job_extensions/interrupt_errors_spec.rb
+++ b/spec/lib/good_job/active_job_extensions/interrupt_errors_spec.rb
@@ -83,7 +83,7 @@ def perform
         expect(initial_discrete_execution).to have_attributes(
           performed_at: be_present,
           finished_at: be_present,
-          duration: be_present,
+          duration: Gem::Version.new(Rails.version) >= Gem::Version.new('6.1.0.a') ? be_present : nil,
           error: start_with('GoodJob::InterruptError: Interrupted after starting perform at'),
           error_event: GoodJob::Job::ERROR_EVENT_INTERRUPTED
         )
@@ -92,7 +92,7 @@ def perform
         expect(retried_discrete_execution).to have_attributes(
           performed_at: be_present,
           finished_at: be_present,
-          duration: be_present,
+          duration: Gem::Version.new(Rails.version) >= Gem::Version.new('6.1.0.a') ? be_present : nil,
           error: start_with('GoodJob::InterruptError: Interrupted after starting perform at'),
           error_event: GoodJob::Job::ERROR_EVENT_RETRIED
         )