diff --git a/go/test/endtoend/vreplication/vdiff2_test.go b/go/test/endtoend/vreplication/vdiff2_test.go
index c03ec675c2e..cb38763b2de 100644
--- a/go/test/endtoend/vreplication/vdiff2_test.go
+++ b/go/test/endtoend/vreplication/vdiff2_test.go
@@ -104,8 +104,7 @@ var testCases = []*testCase{
 }
 
 func TestVDiff2(t *testing.T) {
-	allCellNames = "zone1"
-	defaultCellName := "zone1"
+	allCellNames = "zone1,zone2,zone3,zone4,zone5"
 	sourceKs := "product"
 	sourceShards := []string{"0"}
 	targetKs := "customer"
@@ -113,14 +112,19 @@ func TestVDiff2(t *testing.T) {
 	// This forces us to use multiple vstream packets even with small test tables
 	extraVTTabletArgs = []string{"--vstream_packet_size=1"}
 
-	vc = NewVitessCluster(t, "TestVDiff2", []string{allCellNames}, mainClusterConfig)
+	vc = NewVitessCluster(t, "TestVDiff2", strings.Split(allCellNames, ","), mainClusterConfig)
 	require.NotNil(t, vc)
-	defaultCell = vc.Cells[defaultCellName]
-	cells := []*Cell{defaultCell}
+	zone1 := vc.Cells["zone1"]
+	zone2 := vc.Cells["zone2"]
+	zone3 := vc.Cells["zone3"]
+	defaultCell = zone1
 
 	defer vc.TearDown(t)
 
-	vc.AddKeyspace(t, cells, sourceKs, strings.Join(sourceShards, ","), initialProductVSchema, initialProductSchema, 0, 0, 100, sourceKsOpts)
+	// The primary tablet is only added in the first cell.
+	// We ONLY add primary tablets in this test.
+	_, err := vc.AddKeyspace(t, []*Cell{zone1, zone2, zone3}, sourceKs, strings.Join(sourceShards, ","), initialProductVSchema, initialProductSchema, 0, 0, 100, sourceKsOpts)
+	require.NoError(t, err)
 
 	vtgate = defaultCell.Vtgates[0]
 	require.NotNil(t, vtgate)
@@ -140,7 +144,9 @@ func TestVDiff2(t *testing.T) {
 
 	generateMoreCustomers(t, sourceKs, 100)
 
-	_, err := vc.AddKeyspace(t, cells, targetKs, strings.Join(targetShards, ","), customerVSchema, customerSchema, 0, 0, 200, targetKsOpts)
+	// The primary tablet is only added in the first cell.
+	// We ONLY add primary tablets in this test.
+	tks, err := vc.AddKeyspace(t, []*Cell{zone2, zone1, zone3}, targetKs, strings.Join(targetShards, ","), customerVSchema, customerSchema, 0, 0, 200, targetKsOpts)
 	require.NoError(t, err)
 	for _, shard := range targetShards {
 		require.NoError(t, cluster.WaitForHealthyShard(vc.VtctldClient, targetKs, shard))
@@ -148,15 +154,15 @@ func TestVDiff2(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			testWorkflow(t, vc, tc, cells)
+			// Primary tablets for any new shards are added in the first cell.
+			testWorkflow(t, vc, tc, tks, []*Cell{zone3, zone2, zone1})
 		})
 	}
 }
 
-func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, cells []*Cell) {
+func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, tks *Keyspace, cells []*Cell) {
 	arrTargetShards := strings.Split(tc.targetShards, ",")
 	if tc.typ == "Reshard" {
-		tks := vc.Cells[cells[0].Name].Keyspaces[tc.targetKs]
 		require.NoError(t, vc.AddShards(t, cells, tks, tc.targetShards, 0, 0, tc.tabletBaseID, targetKsOpts))
 		for _, shard := range arrTargetShards {
 			require.NoError(t, cluster.WaitForHealthyShard(vc.VtctldClient, tc.targetKs, shard))
@@ -169,6 +175,7 @@ func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, cells []*Cell)
 	if tc.typ == "Reshard" {
 		args = append(args, "--source_shards", tc.sourceShards, "--target_shards", tc.targetShards)
 	}
+	args = append(args, "--cells", allCellNames)
 	args = append(args, "--tables", tc.tables)
 	args = append(args, "Create")
 	args = append(args, ksWorkflow)
@@ -180,7 +187,7 @@ func testWorkflow(t *testing.T, vc *VitessCluster, tc *testCase, cells []*Cell)
 		catchup(t, tab, tc.workflow, tc.typ)
 	}
 
-	vdiff(t, tc.targetKs, tc.workflow, cells[0].Name, true, true, nil)
+	vdiff(t, tc.targetKs, tc.workflow, allCellNames, true, true, nil)
 
 	if tc.autoRetryError {
 		testAutoRetryError(t, tc, cells[0].Name)
diff --git a/go/vt/vttablet/tabletmanager/vdiff/action_test.go b/go/vt/vttablet/tabletmanager/vdiff/action_test.go
index 6c3106f5310..4a66e19924a 100644
--- a/go/vt/vttablet/tabletmanager/vdiff/action_test.go
+++ b/go/vt/vttablet/tabletmanager/vdiff/action_test.go
@@ -70,14 +70,14 @@ func TestPerformVDiffAction(t *testing.T) {
 			// available cells, so this additional cell should then show up in the
 			// created vdiff record.
 			preFunc: func() error {
-				return tstenv.TopoServ.CreateCellInfo(ctx, "zone100_test", &topodatapb.CellInfo{})
+				return tstenv.TopoServ.CreateCellInfo(ctx, "cell1_test", &topodatapb.CellInfo{})
 			},
 			expectQueries: []string{
 				fmt.Sprintf("select id as id from _vt.vdiff where vdiff_uuid = %s", encodeString(uuid)),
-				fmt.Sprintf(`insert into _vt.vdiff(keyspace, workflow, state, options, shard, db_name, vdiff_uuid) values('', '', 'pending', '{\"picker_options\":{\"source_cell\":\"cell1,zone100_test\",\"target_cell\":\"cell1,zone100_test\"}}', '0', 'vt_vttest', %s)`, encodeString(uuid)),
+				fmt.Sprintf(`insert into _vt.vdiff(keyspace, workflow, state, options, shard, db_name, vdiff_uuid) values('', '', 'pending', '{\"picker_options\":{\"source_cell\":\"cell1,cell1_test,cell2,cell3\",\"target_cell\":\"cell1,cell1_test,cell2,cell3\"}}', '0', 'vt_vttest', %s)`, encodeString(uuid)),
 			},
 			postFunc: func() error {
-				return tstenv.TopoServ.DeleteCellInfo(ctx, "zone100_test", true)
+				return tstenv.TopoServ.DeleteCellInfo(ctx, "cell1_test", true)
 			},
 		},
 		{
@@ -94,10 +94,10 @@ func TestPerformVDiffAction(t *testing.T) {
 			},
 			// Add a second cell and create an cell alias that contains it.
 			preFunc: func() error {
-				if err := tstenv.TopoServ.CreateCellInfo(ctx, "zone100_test", &topodatapb.CellInfo{}); err != nil {
+				if err := tstenv.TopoServ.CreateCellInfo(ctx, "cell1_test", &topodatapb.CellInfo{}); err != nil {
 					return err
 				}
-				cells := append(tstenv.Cells, "zone100_test")
+				cells := append(tstenv.Cells, "cell1_test")
 				return tstenv.TopoServ.CreateCellsAlias(ctx, "all", &topodatapb.CellsAlias{
 					Cells: cells,
 				})
@@ -107,7 +107,7 @@ func TestPerformVDiffAction(t *testing.T) {
 				fmt.Sprintf(`insert into _vt.vdiff(keyspace, workflow, state, options, shard, db_name, vdiff_uuid) values('', '', 'pending', '{\"picker_options\":{\"source_cell\":\"all\",\"target_cell\":\"all\"}}', '0', 'vt_vttest', %s)`, encodeString(uuid)),
 			},
 			postFunc: func() error {
-				if err := tstenv.TopoServ.DeleteCellInfo(ctx, "zone100_test", true); err != nil {
+				if err := tstenv.TopoServ.DeleteCellInfo(ctx, "cell1_test", true); err != nil {
 					return err
 				}
 				return tstenv.TopoServ.DeleteCellsAlias(ctx, "all")
diff --git a/go/vt/vttablet/tabletmanager/vdiff/engine_test.go b/go/vt/vttablet/tabletmanager/vdiff/engine_test.go
index fda37187031..cf77502fb32 100644
--- a/go/vt/vttablet/tabletmanager/vdiff/engine_test.go
+++ b/go/vt/vttablet/tabletmanager/vdiff/engine_test.go
@@ -19,6 +19,7 @@ package vdiff
 import (
 	"context"
 	"fmt"
+	"strings"
 	"testing"
 
 	"github.com/google/uuid"
@@ -107,8 +108,8 @@ func TestVDiff(t *testing.T) {
 			MaxRows:        100,
 		},
 		PickerOptions: &tabletmanagerdatapb.VDiffPickerOptions{
-			SourceCell:  tstenv.Cells[0],
-			TargetCell:  tstenv.Cells[0],
+			SourceCell:  strings.Join(tstenv.Cells, ","),
+			TargetCell:  strings.Join(tstenv.Cells, ","),
 			TabletTypes: "primary",
 		},
 		ReportOptions: &tabletmanagerdatapb.VDiffReportOptions{
diff --git a/go/vt/vttablet/tabletmanager/vdiff/table_differ.go b/go/vt/vttablet/tabletmanager/vdiff/table_differ.go
index 66043dabe6d..b703c60e087 100644
--- a/go/vt/vttablet/tabletmanager/vdiff/table_differ.go
+++ b/go/vt/vttablet/tabletmanager/vdiff/table_differ.go
@@ -210,9 +210,6 @@ func (td *tableDiffer) selectTablets(ctx context.Context) error {
 	sourceCells := strings.Split(td.wd.opts.PickerOptions.SourceCell, ",")
 	targetCells := strings.Split(td.wd.opts.PickerOptions.TargetCell, ",")
 
-	log.Errorf("DEBUG: sourceCells: %v", sourceCells)
-	log.Errorf("DEBUG: targetCells: %v", sourceCells)
-
 	// For Mount+Migrate, the source tablets will be in a different
 	// Vitess cluster with its own TopoServer.
 	sourceTopoServer := td.wd.ct.ts
diff --git a/go/vt/vttablet/tabletserver/vstreamer/testenv/testenv.go b/go/vt/vttablet/tabletserver/vstreamer/testenv/testenv.go
index c40e180110f..e9c0eaaeede 100644
--- a/go/vt/vttablet/tabletserver/vstreamer/testenv/testenv.go
+++ b/go/vt/vttablet/tabletserver/vstreamer/testenv/testenv.go
@@ -65,7 +65,7 @@ func Init(ctx context.Context) (*Env, error) {
 	te := &Env{
 		KeyspaceName: "vttest",
 		ShardName:    "0",
-		Cells:        []string{"cell1"},
+		Cells:        []string{"cell1", "cell2", "cell3"},
 	}
 
 	te.TopoServ = memorytopo.NewServer(ctx, te.Cells...)