diff --git a/internal/activity.go b/internal/activity.go
index 5a7fe749a..03d2d9f24 100644
--- a/internal/activity.go
+++ b/internal/activity.go
@@ -100,7 +100,6 @@ type (
 		// better to rely on the default value.
 		// ScheduleToStartTimeout is always non-retryable. Retrying after this timeout doesn't make sense as it would
 		// just put the Activity Task back into the same Task Queue.
-		// If ScheduleToClose is not provided then this timeout is required.
 		// Optional: Defaults to unlimited.
 		ScheduleToStartTimeout time.Duration
 
@@ -109,7 +108,7 @@ type (
 		// to detect that an Activity that didn't complete on time. So this timeout should be as short as the longest
 		// possible execution of the Activity body. Potentially long running Activities must specify HeartbeatTimeout
 		// and call Activity.RecordHeartbeat(ctx, "my-heartbeat") periodically for timely failure detection.
-		// If ScheduleToClose is not provided then this timeout is required: Defaults to the ScheduleToCloseTimeout value.
+		// Either this option or ScheduleToClose is required: Defaults to the ScheduleToCloseTimeout value.
 		StartToCloseTimeout time.Duration
 
 		// HeartbeatTimeout - Heartbeat interval. Activity must call Activity.RecordHeartbeat(ctx, "my-heartbeat")
diff --git a/test/integration_test.go b/test/integration_test.go
index 88f516962..b06d36c7a 100644
--- a/test/integration_test.go
+++ b/test/integration_test.go
@@ -1142,6 +1142,22 @@ func (ts *IntegrationTestSuite) TestWorkflowWithParallelSideEffects() {
 	ts.NoError(ts.executeWorkflow("test-wf-parallel-side-effects", ts.workflows.WorkflowWithParallelSideEffects, nil))
 }
 
+func (ts *IntegrationTestSuite) TestActivityTimeoutsWorkflow() {
+	ts.NoError(ts.executeWorkflow("test-activity-timeout-workflow", ts.workflows.ActivityTimeoutsWorkflow, nil, workflow.ActivityOptions{
+		ScheduleToCloseTimeout: 5 * time.Second,
+	}))
+
+	ts.NoError(ts.executeWorkflow("test-activity-timeout-workflow", ts.workflows.ActivityTimeoutsWorkflow, nil, workflow.ActivityOptions{
+		StartToCloseTimeout: 5 * time.Second,
+	}))
+
+	ts.Error(ts.executeWorkflow("test-activity-timeout-workflow", ts.workflows.ActivityTimeoutsWorkflow, nil, workflow.ActivityOptions{}))
+	ts.Error(ts.executeWorkflow("test-activity-timeout-workflow", ts.workflows.ActivityTimeoutsWorkflow, nil, workflow.ActivityOptions{
+		ScheduleToStartTimeout: 5 * time.Second,
+	}))
+
+}
+
 func (ts *IntegrationTestSuite) TestWorkflowWithParallelSideEffectsUsingReplay() {
 	replayer := worker.NewWorkflowReplayer()
 	replayer.RegisterWorkflowWithOptions(ts.workflows.WorkflowWithParallelSideEffects, workflow.RegisterOptions{DisableAlreadyRegisteredCheck: true})
diff --git a/test/workflow_test.go b/test/workflow_test.go
index 89f303492..8319b17f0 100644
--- a/test/workflow_test.go
+++ b/test/workflow_test.go
@@ -948,6 +948,10 @@ func (w *Workflows) ConsistentQueryWorkflow(ctx workflow.Context, delay time.Dur
 	return nil
 }
 
+func (w *Workflows) ActivityTimeoutsWorkflow(ctx workflow.Context, activityOptions workflow.ActivityOptions) error {
+	activityCtx := workflow.WithActivityOptions(ctx, activityOptions)
+	return workflow.ExecuteActivity(activityCtx, "Sleep", time.Second).Get(ctx, nil)
+}
 func (w *Workflows) SignalWorkflow(ctx workflow.Context) (*commonpb.WorkflowType, error) {
 	s := workflow.NewSelector(ctx)
 
@@ -2289,6 +2293,7 @@ func (w *Workflows) register(worker worker.Worker) {
 	worker.RegisterWorkflow(w.UpdateInfoWorkflow)
 	worker.RegisterWorkflow(w.SignalWorkflow)
 	worker.RegisterWorkflow(w.CronWorkflow)
+	worker.RegisterWorkflow(w.ActivityTimeoutsWorkflow)
 	worker.RegisterWorkflow(w.CancelTimerConcurrentWithOtherCommandWorkflow)
 	worker.RegisterWorkflow(w.CancelMultipleCommandsOverMultipleTasks)
 	worker.RegisterWorkflow(w.CancelChildAndExecuteActivityRace)