diff --git a/reconciler/testing/table.go b/reconciler/testing/table.go
index f749746633..85cc047f52 100644
--- a/reconciler/testing/table.go
+++ b/reconciler/testing/table.go
@@ -29,6 +29,8 @@ import (
 	"go.uber.org/zap"
 
 	"k8s.io/apimachinery/pkg/api/resource"
+	"k8s.io/apimachinery/pkg/fields"
+	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/util/sets"
 	clientgotesting "k8s.io/client-go/testing"
@@ -133,6 +135,25 @@ func objKey(o runtime.Object) string {
 	return path.Join(typeOf, on.GetNamespace(), on.GetName())
 }
 
+// deleteCollectionKey builds a unique string representing a DeleteCollection
+// call, so that got and want calls can be compared as sets.
+func deleteCollectionKey(a clientgotesting.DeleteCollectionAction, skipNamespaceValidation bool) string {
+	lr := a.GetListRestrictions()
+	labelSelector, fieldSelector := lr.Labels, lr.Fields
+	if labelSelector == nil {
+		labelSelector = labels.Everything()
+	}
+	if fieldSelector == nil {
+		fieldSelector = fields.Everything()
+	}
+
+	n := a.GetResource().Resource + "~~" + labelSelector.String() + "~~" + fieldSelector.String()
+	if !skipNamespaceValidation {
+		n += "~~" + a.GetNamespace()
+	}
+	return n
+}
+
 // Factory returns a Reconciler.Interface to perform reconciliation in table test, and
 // ActionRecorderList/EventList to capture k8s actions/events produced during reconciliation.
 type Factory func(*testing.T, *TableRow) (controller.Reconciler, ActionRecorderList, EventList)
@@ -316,6 +337,27 @@ func (r *TableRow) Test(t *testing.T, factory Factory) {
 		}
 	}
 
+	// Build a set of unique strings that represent type{-namespace}-labelSelector-fieldSelector
+	// to catch missing or unexpected DeleteCollection calls.
+	gotDeleteCollections := make(sets.Set[string], len(actions.DeleteCollections))
+	for _, w := range actions.DeleteCollections {
+		n := deleteCollectionKey(w, r.SkipNamespaceValidation)
+		gotDeleteCollections.Insert(n)
+	}
+	wantDeleteCollections := make(sets.Set[string], len(r.WantDeleteCollections))
+	for _, w := range r.WantDeleteCollections {
+		n := deleteCollectionKey(w, r.SkipNamespaceValidation)
+		wantDeleteCollections.Insert(n)
+	}
+	if !gotDeleteCollections.Equal(wantDeleteCollections) {
+		if extra := gotDeleteCollections.Difference(wantDeleteCollections); len(extra) > 0 {
+			t.Error("Extra or unexpected delete-collections:", extra.UnsortedList())
+		}
+		if missing := wantDeleteCollections.Difference(gotDeleteCollections); len(missing) > 0 {
+			t.Error("Missing delete-collections:", missing.UnsortedList())
+		}
+	}
+
 	for i, want := range r.WantPatches {
 		if i >= len(actions.Patches) {
 			t.Errorf("Missing patch: %#v; raw: %s", want, string(want.GetPatch()))
diff --git a/reconciler/testing/table_test.go b/reconciler/testing/table_test.go
new file mode 100644
index 0000000000..5e93fe16d9
--- /dev/null
+++ b/reconciler/testing/table_test.go
@@ -0,0 +1,70 @@
+/*
+Copyright 2026 The Knative Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package testing
+
+import (
+	"testing"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	clientgotesting "k8s.io/client-go/testing"
+)
+
+func TestDeleteCollectionKey(t *testing.T) {
+	gvr := schema.GroupVersionResource{Resource: "pods"}
+
+	fromListOptions := clientgotesting.NewDeleteCollectionAction(gvr, "foo", metav1.ListOptions{LabelSelector: "app=foo"})
+	literalWithSelector := clientgotesting.DeleteCollectionActionImpl{
+		ActionImpl: clientgotesting.ActionImpl{
+			Namespace: "foo",
+			Resource:  gvr,
+		},
+		ListRestrictions: clientgotesting.ListRestrictions{
+			Labels: labels.SelectorFromSet(labels.Set{"app": "foo"}),
+		},
+	}
+	literalWithoutSelector := clientgotesting.DeleteCollectionActionImpl{
+		ActionImpl: clientgotesting.ActionImpl{
+			Namespace: "foo",
+			Resource:  gvr,
+		},
+	}
+	otherNamespace := clientgotesting.NewDeleteCollectionAction(gvr, "bar", metav1.ListOptions{LabelSelector: "app=foo"})
+
+	// An action built via the constructor (as the fake clientset produces) and an
+	// equivalent hand-built literal (as a test author would write in WantDeleteCollections)
+	// must key identically, or a correct WantDeleteCollections would never match.
+	if got, want := deleteCollectionKey(fromListOptions, false), deleteCollectionKey(literalWithSelector, false); got != want {
+		t.Errorf("deleteCollectionKey() = %q, want %q", got, want)
+	}
+
+	// A DeleteCollection call with no selector at all (nil Labels/Fields) must not panic,
+	// and must key the same as an explicit "everything" selector.
+	everything := clientgotesting.NewDeleteCollectionAction(gvr, "foo", metav1.ListOptions{})
+	if got, want := deleteCollectionKey(literalWithoutSelector, false), deleteCollectionKey(everything, false); got != want {
+		t.Errorf("deleteCollectionKey() = %q, want %q", got, want)
+	}
+
+	// Differing namespaces must produce different keys unless namespace validation is skipped.
+	if got := deleteCollectionKey(fromListOptions, false); got == deleteCollectionKey(otherNamespace, false) {
+		t.Errorf("deleteCollectionKey() = %q, want distinct keys for different namespaces", got)
+	}
+	if got, want := deleteCollectionKey(fromListOptions, true), deleteCollectionKey(otherNamespace, true); got != want {
+		t.Errorf("deleteCollectionKey() = %q, want %q when SkipNamespaceValidation is set", got, want)
+	}
+}