diff --git a/pkg/controllers/workgenerator/envelope.go b/pkg/controllers/workgenerator/envelope.go
index a7d2f5a8e..05518f98c 100644
--- a/pkg/controllers/workgenerator/envelope.go
+++ b/pkg/controllers/workgenerator/envelope.go
@@ -62,10 +62,10 @@ func (r *Reconciler) createOrUpdateEnvelopeCRWorkObj(
 		fleetv1beta1.PlacementTrackingLabel: binding.GetLabels()[fleetv1beta1.PlacementTrackingLabel],
 		fleetv1beta1.EnvelopeTypeLabel:      envelopeReader.GetEnvelopeType(),
 		fleetv1beta1.EnvelopeNameLabel:      envelopeReader.GetName(),
-		fleetv1beta1.EnvelopeNamespaceLabel: envelopeReader.GetNamespace(),
 	}
 	// Add ParentNamespaceLabel if the binding is namespaced
 	if binding.GetNamespace() != "" {
+		labelMatcher[fleetv1beta1.EnvelopeNamespaceLabel] = envelopeReader.GetNamespace()
 		labelMatcher[fleetv1beta1.ParentNamespaceLabel] = binding.GetNamespace()
 	}
 	workList := &fleetv1beta1.WorkList{}
@@ -87,6 +87,12 @@ func (r *Reconciler) createOrUpdateEnvelopeCRWorkObj(
 			"resourceBinding", klog.KObj(binding),
 			"resourceSnapshot", klog.KObj(resourceSnapshot),
 			"envelope", envelopeReader.GetEnvelopeObjRef())
+		// Log the work object names to help debug.
+		workNames := make([]string, len(workList.Items))
+		for i := range workList.Items {
+			workNames[i] = workList.Items[i].Name
+		}
+		klog.ErrorS(wrappedErr, "Duplicate work objects found", "works", workNames)
 		return nil, controller.NewUnexpectedBehaviorError(wrappedErr)
 	case len(workList.Items) == 1:
 		klog.V(2).InfoS("Found existing work object for the envelope; updating it",
diff --git a/pkg/controllers/workgenerator/envelope_test.go b/pkg/controllers/workgenerator/envelope_test.go
index 310553777..c8b112a53 100644
--- a/pkg/controllers/workgenerator/envelope_test.go
+++ b/pkg/controllers/workgenerator/envelope_test.go
@@ -483,6 +483,18 @@ func TestCreateOrUpdateEnvelopeCRWorkObj(t *testing.T) {
 			want:                                nil,
 			wantErr:                             true,
 		},
+		{
+			name:                                "two existing works should result in error",
+			envelopeReader:                      resourceEnvelope,
+			resourceOverrideSnapshotHash:        "new-resource-hash",
+			clusterResourceOverrideSnapshotHash: "new-cluster-resource-hash",
+			existingObjects: func() []client.Object {
+				existingWork1 := existingWork.DeepCopy()
+				existingWork1.Name = "test-work-1"
+				return []client.Object{existingWork, existingWork1}
+			}(),
+			wantErr: true,
+		},
 	}
 
 	for _, tt := range tests {