diff --git a/cmd/worker/workercmd/cmd.go b/cmd/worker/workercmd/cmd.go
index 2aa2522d..c4195d7b 100644
--- a/cmd/worker/workercmd/cmd.go
+++ b/cmd/worker/workercmd/cmd.go
@@ -70,6 +70,10 @@ func (m *Main) Run(ctx context.Context) error {
 		activities.NewMetadataValidationActivity().Execute,
 		temporalsdk_activity.RegisterOptions{Name: activities.MetadataValidationName},
 	)
+	w.RegisterActivityWithOptions(
+		activities.CombinePremisActivity().Execute,
+		temporalsdk_activity.RegisterOptions{Name: activities.CombinePremisName},
+	)
 	w.RegisterActivityWithOptions(
 		activities.NewSipCreationActivity().Execute,
 		temporalsdk_activity.RegisterOptions{Name: activities.SipCreationName},
diff --git a/internal/workflow/preprocessing.go b/internal/workflow/preprocessing.go
index 40be3d33..c97aedc1 100644
--- a/internal/workflow/preprocessing.go
+++ b/internal/workflow/preprocessing.go
@@ -102,6 +102,16 @@ func (w *PreprocessingWorkflow) Execute(
 		return nil, e
 	}
 
+	// Combine PREMIS files into one
+	var combinePremis activities.CombinePremisResult
+	e = temporalsdk_workflow.ExecuteActivity(withLocalActOpts(ctx), activities.CombinePremisName, &activities.CombinePremisParams{
+		SipPath: localPath,
+	}).
+		Get(ctx, &combinePremis)
+	if e != nil {
+		return nil, e
+	}
+
 	// Repackage SFA SIP into a Bag.
 	var sipCreation activities.SipCreationResult
 	e = temporalsdk_workflow.ExecuteActivity(withLocalActOpts(ctx), activities.SipCreationName, &activities.SipCreationParams{