diff --git a/pkg/hnsw/hnsw_test.go b/pkg/hnsw/hnsw_test.go
index 6e55f87..9896acb 100644
--- a/pkg/hnsw/hnsw_test.go
+++ b/pkg/hnsw/hnsw_test.go
@@ -2,6 +2,7 @@ package hnsw
 
 import (
 	"fmt"
+	"reflect"
 	"testing"
 )
 
@@ -492,3 +493,80 @@ func TestSpawnLevelDistribution(t *testing.T) {
 		fmt.Printf("levels distribution: %v\n", levels)
 	})
 }
+
+func TestHnsw_KnnCluster(t *testing.T) {
+
+	var clusterC = []Vector{
+		{0.2, 0.5},
+		{0.2, 0.7},
+		{0.3, 0.8},
+		{0.5, 0.5},
+		{0.4, 0.1},
+	}
+
+	var clusterCNodes = map[NodeId][]NodeId{
+		1: {2, 4, 3, 5},
+		2: {3, 1, 4, 5},
+		3: {2, 1, 4, 5},
+		4: {1, 2, 3, 5},
+		5: {4, 1, 2, 3},
+	}
+
+	var clusterCVisited = map[NodeId][]bool{
+		1: {false, true, true, true, true, true},
+		2: {false, false, true, true, true, true},
+		3: {false, false, false, true, true, true},
+		4: {false, true, true, true, false, true},
+		5: {false, true, true, true, true, false},
+	}
+
+	t.Run("cluster c insert", func(t *testing.T) {
+		h := NewHNSW(2, 4, 4, []float32{0, 0})
+
+		for i, q := range clusterC {
+			if err := h.Insert(q); err != nil {
+				t.Fatalf("failed to insert item %d: %v", i, err)
+			}
+		}
+
+		fmt.Printf("%v", h.Nodes)
+
+		if reflect.DeepEqual(h.Nodes, clusterCNodes) {
+			t.Fatalf("expected all node keys to be the same as clusterC")
+		}
+
+		if len(h.Nodes) != 6 {
+			t.Fatalf("expected 6 nodes, got %d", len(h.Nodes))
+		}
+
+		for i := 1; i <= 5; i++ {
+			nodeId := NodeId(i)
+			node := h.Nodes[nodeId]
+
+			var nodeNN []NodeId
+			visitedNN := make([]bool, 6) // counting entry
+
+			for level := node.level; level >= 0; level-- {
+				friendsAtLevel := node.friends[level]
+
+				for !friendsAtLevel.IsEmpty() {
+					peeled, err := friendsAtLevel.Peel()
+					if err != nil {
+						t.Fatal(err)
+					}
+
+					if !visitedNN[peeled.id] {
+						nodeNN = append(nodeNN, peeled.id)
+						visitedNN[peeled.id] = true
+					}
+				}
+			}
+
+			if reflect.DeepEqual(clusterCVisited[nodeId], visitedNN) {
+				t.Fatalf("expected all node keys to be the same as clusterC")
+			}
+		}
+
+	})
+
+}