diff --git a/api/bolt/migrator/migrate_ce.go b/api/bolt/migrator/migrate_ce.go
index 7f2b70586..26f751ae1 100644
--- a/api/bolt/migrator/migrate_ce.go
+++ b/api/bolt/migrator/migrate_ce.go
@@ -301,7 +301,7 @@ func (m *Migrator) Migrate() error {
 		}
 	}
 
-	// Portainer 2.9.1
+	// Portainer 2.9.1, 2.9.2
 	if m.currentDBVersion < 33 {
 		err := m.migrateDBVersionToDB33()
 		if err != nil {
@@ -316,6 +316,13 @@ func (m *Migrator) Migrate() error {
 		}
 	}
 
+	// Portainer 2.9.3 (yep out of order, but 2.10 is EE only)
+	if m.currentDBVersion < 35 {
+		if err := m.migrateDBVersionToDB35(); err != nil {
+			return migrationError(err, "migrateDBVersionToDB35")
+		}
+	}
+
 	err = m.versionService.StoreDBVersion(portainer.DBVersion)
 	if err != nil {
 		return migrationError(err, "StoreDBVersion")
diff --git a/api/bolt/migrator/migrate_dbversion31.go b/api/bolt/migrator/migrate_dbversion31.go
index 5993f0513..af80ce25f 100644
--- a/api/bolt/migrator/migrate_dbversion31.go
+++ b/api/bolt/migrator/migrate_dbversion31.go
@@ -100,6 +100,32 @@ func (m *Migrator) updateDockerhubToDB32() error {
 		RegistryAccesses: portainer.RegistryAccesses{},
 	}
 
+	// The following code will make this function idempotent.
+	// i.e. if run again, it will not change the data.  It will ensure that
+	// we only have one migrated registry entry. Duplicates will be removed
+	// if they exist and which has been happening due to earlier migration bugs
+	migrated := false
+	registries, _ := m.registryService.Registries()
+	for _, r := range registries {
+		if r.Type == registry.Type &&
+			r.Name == registry.Name &&
+			r.URL == registry.URL &&
+			r.Authentication == registry.Authentication {
+
+			if !migrated {
+				// keep this one entry
+				migrated = true
+			} else {
+				// delete subsequent duplicates
+				m.registryService.DeleteRegistry(portainer.RegistryID(r.ID))
+			}
+		}
+	}
+
+	if migrated {
+		return nil
+	}
+
 	endpoints, err := m.endpointService.Endpoints()
 	if err != nil {
 		return err
diff --git a/api/bolt/migrator/migrate_dbversion34.go b/api/bolt/migrator/migrate_dbversion34.go
new file mode 100644
index 000000000..78a785051
--- /dev/null
+++ b/api/bolt/migrator/migrate_dbversion34.go
@@ -0,0 +1,11 @@
+package migrator
+
+func (m *Migrator) migrateDBVersionToDB35() error {
+	// These should have been migrated already, but due to an earlier bug and a bunch of duplicates,
+	// calling it again will now fix the issue as the function has been repaired.
+	err := m.updateDockerhubToDB32()
+	if err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/api/bolt/migrator/migrate_dbversion34_test.go b/api/bolt/migrator/migrate_dbversion34_test.go
new file mode 100644
index 000000000..59819ee42
--- /dev/null
+++ b/api/bolt/migrator/migrate_dbversion34_test.go
@@ -0,0 +1,108 @@
+package migrator
+
+import (
+	"os"
+	"path"
+	"testing"
+	"time"
+
+	"github.com/boltdb/bolt"
+	portainer "github.com/portainer/portainer/api"
+	"github.com/portainer/portainer/api/bolt/dockerhub"
+	"github.com/portainer/portainer/api/bolt/endpoint"
+	"github.com/portainer/portainer/api/bolt/internal"
+	"github.com/portainer/portainer/api/bolt/registry"
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	db35TestFile = "portainer-mig-35.db"
+	username     = "portainer"
+	password     = "password"
+)
+
+func setupDB35Test(t *testing.T) *Migrator {
+	is := assert.New(t)
+	dbConn, err := bolt.Open(path.Join(t.TempDir(), db35TestFile), 0600, &bolt.Options{Timeout: 1 * time.Second})
+	is.NoError(err, "failed to init testing DB connection")
+
+	// Create an old style dockerhub authenticated account
+	dockerhubService, err := dockerhub.NewService(&internal.DbConnection{DB: dbConn})
+	is.NoError(err, "failed to init testing registry service")
+	err = dockerhubService.UpdateDockerHub(&portainer.DockerHub{true, username, password})
+	is.NoError(err, "failed to create dockerhub account")
+
+	registryService, err := registry.NewService(&internal.DbConnection{DB: dbConn})
+	is.NoError(err, "failed to init testing registry service")
+
+	endpointService, err := endpoint.NewService(&internal.DbConnection{DB: dbConn})
+	is.NoError(err, "failed to init endpoint service")
+
+	m := &Migrator{
+		db:               dbConn,
+		dockerhubService: dockerhubService,
+		registryService:  registryService,
+		endpointService:  endpointService,
+	}
+
+	return m
+}
+
+// TestUpdateDockerhubToDB32 tests a normal upgrade
+func TestUpdateDockerhubToDB32(t *testing.T) {
+	is := assert.New(t)
+	m := setupDB35Test(t)
+	defer m.db.Close()
+	defer os.Remove(db35TestFile)
+
+	if err := m.updateDockerhubToDB32(); err != nil {
+		t.Errorf("failed to update settings: %v", err)
+	}
+
+	// Verify we have a single registry were created
+	registries, err := m.registryService.Registries()
+	is.NoError(err, "failed to read registries from the RegistryService")
+	is.Equal(len(registries), 1, "only one migrated registry expected")
+}
+
+// TestUpdateDockerhubToDB32_with_duplicate_migrations tests an upgrade where in earlier versions a broken migration
+// created a large number of duplicate "dockerhub migrated" registry entries.
+func TestUpdateDockerhubToDB32_with_duplicate_migrations(t *testing.T) {
+	is := assert.New(t)
+	m := setupDB35Test(t)
+	defer m.db.Close()
+	defer os.Remove(db35TestFile)
+
+	// Create lots of duplicate entries...
+	registry := &portainer.Registry{
+		Type:             portainer.DockerHubRegistry,
+		Name:             "Dockerhub (authenticated - migrated)",
+		URL:              "docker.io",
+		Authentication:   true,
+		Username:         "portainer",
+		Password:         "password",
+		RegistryAccesses: portainer.RegistryAccesses{},
+	}
+
+	for i := 1; i < 150; i++ {
+		err := m.registryService.CreateRegistry(registry)
+		assert.NoError(t, err, "create registry failed")
+	}
+
+	// Verify they were created
+	registries, err := m.registryService.Registries()
+	is.NoError(err, "failed to read registries from the RegistryService")
+	is.Condition(func() bool {
+		return len(registries) > 1
+	}, "expected multiple duplicate registry entries")
+
+	// Now run the migrator
+	if err := m.updateDockerhubToDB32(); err != nil {
+		t.Errorf("failed to update settings: %v", err)
+	}
+
+	// Verify we have a single registry were created
+	registries, err = m.registryService.Registries()
+	is.NoError(err, "failed to read registries from the RegistryService")
+	is.Equal(len(registries), 1, "only one migrated registry expected")
+}
diff --git a/api/portainer.go b/api/portainer.go
index 7c0b908c1..b37e8ab7d 100644
--- a/api/portainer.go
+++ b/api/portainer.go
@@ -1478,7 +1478,7 @@ const (
 	// APIVersion is the version number of the Portainer API
 	APIVersion = "2.9.3"
 	// DBVersion is the version number of the Portainer database
-	DBVersion = 33
+	DBVersion = 35
 	// ComposeSyntaxMaxVersion is a maximum supported version of the docker compose syntax
 	ComposeSyntaxMaxVersion = "3.9"
 	// AssetsServerURL represents the URL of the Portainer asset server