diff --git a/operators/multiclusterobservability/controllers/placementrule/manifestwork.go b/operators/multiclusterobservability/controllers/placementrule/manifestwork.go
index 434a610e7..51040e785 100644
--- a/operators/multiclusterobservability/controllers/placementrule/manifestwork.go
+++ b/operators/multiclusterobservability/controllers/placementrule/manifestwork.go
@@ -983,28 +983,28 @@ func getObservabilityAddon(c client.Client, namespace string,
 		found.Annotations = make(map[string]string)
 	}
 
-	if _, ok := found.Annotations["observability.open-cluster-management.io/addon-source"]; !ok {
-		found.Annotations["observability.open-cluster-management.io/addon-source"] = "mco"
+	if _, ok := found.Annotations[addonSourceAnnotation]; !ok {
+		found.Annotations[addonSourceAnnotation] = "mco"
 	}
 
-	if found.Annotations["observability.open-cluster-management.io/addon-source"] == "mco" {
+	if found.Annotations[addonSourceAnnotation] == "mco" {
 		addon.Spec.EnableMetrics = mco.Spec.ObservabilityAddonSpec.EnableMetrics
 		addon.Spec.Interval = mco.Spec.ObservabilityAddonSpec.Interval
 		addon.Spec.ScrapeSizeLimitBytes = mco.Spec.ObservabilityAddonSpec.ScrapeSizeLimitBytes
 		addon.Spec.Workers = mco.Spec.ObservabilityAddonSpec.Workers
 		addon.Spec.Resources = config.GetOBAResources(mco.Spec.ObservabilityAddonSpec, mco.Spec.InstanceSize)
 
-		addon.Annotations["observability.open-cluster-management.io/addon-source"] = "mco"
+		addon.Annotations[addonSourceAnnotation] = "mco"
 	}
 
-	if found.Annotations["observability.open-cluster-management.io/addon-source"] == "override" {
+	if found.Annotations[addonSourceAnnotation] == "override" {
 		addon.Spec.EnableMetrics = found.Spec.EnableMetrics
 		addon.Spec.Interval = found.Spec.Interval
 		addon.Spec.ScrapeSizeLimitBytes = found.Spec.ScrapeSizeLimitBytes
 		addon.Spec.Workers = found.Spec.Workers
 		addon.Spec.Resources = found.Spec.Resources
 
-		addon.Annotations["observability.open-cluster-management.io/addon-source"] = "override"
+		addon.Annotations[addonSourceAnnotation] = "override"
 	}
 
 	return addon, nil
diff --git a/operators/multiclusterobservability/controllers/placementrule/manifestwork_test.go b/operators/multiclusterobservability/controllers/placementrule/manifestwork_test.go
index eb419e448..1ec14a578 100644
--- a/operators/multiclusterobservability/controllers/placementrule/manifestwork_test.go
+++ b/operators/multiclusterobservability/controllers/placementrule/manifestwork_test.go
@@ -33,7 +33,7 @@ import (
 
 const (
 	pullSecretName = "test-pull-secret"
-	workSize       = 13
+	workSize       = 14
 )
 
 func init() {
diff --git a/operators/multiclusterobservability/controllers/placementrule/obsaddon.go b/operators/multiclusterobservability/controllers/placementrule/obsaddon.go
index 2b5a1d299..0af345ca8 100644
--- a/operators/multiclusterobservability/controllers/placementrule/obsaddon.go
+++ b/operators/multiclusterobservability/controllers/placementrule/obsaddon.go
@@ -22,8 +22,9 @@ import (
 )
 
 const (
-	obsAddonName      = "observability-addon"
-	obsAddonFinalizer = "observability.open-cluster-management.io/addon-cleanup"
+	obsAddonName          = "observability-addon"
+	obsAddonFinalizer     = "observability.open-cluster-management.io/addon-cleanup"
+	addonSourceAnnotation = "observability.open-cluster-management.io/addon-source"
 )
 
 func deleteObsAddon(c client.Client, namespace string) error {
@@ -75,7 +76,7 @@ func createObsAddon(mco *mcov1beta2.MultiClusterObservability, c client.Client,
 			Name:      obsAddonName,
 			Namespace: namespace,
 			Annotations: map[string]string{
-				"observability.open-cluster-management.io/addon-source": "mco",
+				addonSourceAnnotation: "mco",
 			},
 			Labels: map[string]string{
 				ownerLabelKey: ownerLabelValue,
@@ -112,7 +113,7 @@ func createObsAddon(mco *mcov1beta2.MultiClusterObservability, c client.Client,
 	}
 
 	// Check if existing addon was created by MCO
-	if found.Annotations != nil && found.Annotations["observability.open-cluster-management.io/addon-source"] == "mco" {
+	if found.Annotations != nil && found.Annotations[addonSourceAnnotation] == "mco" {
 		// Only update if specs are different
 		if found.Spec != ec.Spec {
 			found.Spec = ec.Spec