diff --git a/internal/controller/kustomization_controller.go b/internal/controller/kustomization_controller.go
index 5432d672..0c8f11f6 100644
--- a/internal/controller/kustomization_controller.go
+++ b/internal/controller/kustomization_controller.go
@@ -95,6 +95,7 @@ type KustomizationReconciler struct {
 	DefaultServiceAccount string
 	KubeConfigOpts        runtimeClient.KubeConfigOptions
 	ConcurrentSSA         int
+	ImplicitSubstitutions bool
 }
 
 // KustomizationReconcilerOptions contains options for the KustomizationReconciler.
@@ -617,6 +618,17 @@ func (r *KustomizationReconciler) build(ctx context.Context,
 			}
 		}
 
+		// add built-in substitutions
+		if r.ImplicitSubstitutions {
+			if obj.Spec.PostBuild == nil {
+				obj.Spec.PostBuild = &kustomizev1.PostBuild{}
+			}
+			if obj.Spec.PostBuild.Substitute == nil {
+				obj.Spec.PostBuild.Substitute = make(map[string]string)
+			}
+			obj.Spec.PostBuild.Substitute["FLUX_LAST_ATTEMPTED_REVISION"] = obj.Status.LastAttemptedRevision
+		}
+
 		// run variable substitutions
 		if obj.Spec.PostBuild != nil {
 			outRes, err := generator.SubstituteVariables(ctx, r.Client, u, res, false)
diff --git a/main.go b/main.go
index 13e8ea91..7eba113f 100644
--- a/main.go
+++ b/main.go
@@ -75,6 +75,7 @@ func init() {
 
 func main() {
 	var (
+		implicitSubstitutions bool
 		metricsAddr           string
 		eventsAddr            string
 		healthAddr            string
@@ -101,6 +102,8 @@ func main() {
 	flag.IntVar(&concurrent, "concurrent", 4, "The number of concurrent kustomize reconciles.")
 	flag.IntVar(&concurrentSSA, "concurrent-ssa", 4, "The number of concurrent server-side apply operations.")
 	flag.DurationVar(&requeueDependency, "requeue-dependency", 30*time.Second, "The interval at which failing dependencies are reevaluated.")
+	flag.BoolVar(&implicitSubstitutions, "implicit-substitutions", false,
+		"Perform substitutions of built-in values such as last-attempted-revision; has side effects of ALWAYS performing substitutions!")
 	flag.BoolVar(&noRemoteBases, "no-remote-bases", false,
 		"Disallow remote bases usage in Kustomize overlays. When this flag is enabled, all resources must refer to local files included in the source artifact.")
 	flag.IntVar(&httpRetry, "http-retry", 9, "The maximum number of retries when failing to fetch artifacts over HTTP.")
@@ -223,6 +226,7 @@ func main() {
 		Metrics:               metricsH,
 		EventRecorder:         eventRecorder,
 		NoCrossNamespaceRefs:  aclOptions.NoCrossNamespaceRefs,
+		ImplicitSubstitutions: implicitSubstitutions,
 		NoRemoteBases:         noRemoteBases,
 		FailFast:              failFast,
 		ConcurrentSSA:         concurrentSSA,