diff --git a/controllers/packagevariants/pkg/controllers/packagevariant/injection.go b/controllers/packagevariants/pkg/controllers/packagevariant/injection.go
index edad6a32..3fbf859d 100644
--- a/controllers/packagevariants/pkg/controllers/packagevariant/injection.go
+++ b/controllers/packagevariants/pkg/controllers/packagevariant/injection.go
@@ -1,4 +1,4 @@
-// Copyright 2023 The kpt and Nephio Authors
+// Copyright 2023-2024 The kpt and Nephio Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
diff --git a/controllers/packagevariants/pkg/controllers/packagevariant/packagevariant_controller.go b/controllers/packagevariants/pkg/controllers/packagevariant/packagevariant_controller.go
index 95774ae2..8b2dda28 100644
--- a/controllers/packagevariants/pkg/controllers/packagevariant/packagevariant_controller.go
+++ b/controllers/packagevariants/pkg/controllers/packagevariant/packagevariant_controller.go
@@ -1,4 +1,4 @@
-// Copyright 2022 The kpt and Nephio Authors
+// Copyright 2023-2024 The kpt and Nephio Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -596,7 +596,15 @@ func (r *PackageVariantReconciler) deletePackageRevision(ctx context.Context, pr
 
 // determine if the downstream PR needs to be updated
 func (r *PackageVariantReconciler) isUpToDate(pv *api.PackageVariant, downstream *porchapi.PackageRevision) bool {
+	if downstream.Status.UpstreamLock == nil {
+		klog.Warningf("status.upstreamLock field is empty/missing in downstream PackageRevision: %s", pv.ObjectMeta.Name)
+		return true
+	}
 	upstreamLock := downstream.Status.UpstreamLock
+	if upstreamLock.Git == nil || upstreamLock.Git.Ref == "" {
+		klog.Warningf("status.upstreamLock.git or status.upstreamLock.git.ref field is empty/missing in downstream PackageRevision: %s", pv.ObjectMeta.Name)
+		return true
+	}
 	lastIndex := strings.LastIndex(upstreamLock.Git.Ref, "/")
 	if strings.HasPrefix(upstreamLock.Git.Ref, "drafts") {
 		// The current upstream is a draft, and the target upstream