diff --git a/cmd/ido2icingadb/main.go b/cmd/ido2icingadb/main.go
index 8b96bbdd..4ec3705b 100644
--- a/cmd/ido2icingadb/main.go
+++ b/cmd/ido2icingadb/main.go
@@ -11,7 +11,6 @@ import (
 	"github.com/goccy/go-yaml"
 	"github.com/icinga/icingadb/pkg/com"
 	"github.com/icinga/icingadb/pkg/config"
-	"github.com/icinga/icingadb/pkg/driver"
 	"github.com/icinga/icingadb/pkg/icingadb"
 	"github.com/icinga/icingadb/pkg/logging"
 	icingadbTypes "github.com/icinga/icingadb/pkg/types"
@@ -25,7 +24,6 @@ import (
 	"os"
 	"path"
 	"regexp"
-	"sync"
 	"time"
 )
 
@@ -279,7 +277,6 @@ func fillCache() {
 // migrate does the actual migration.
 func migrate(c *Config, idb *icingadb.DB, envId []byte) {
 	endpointId := sha1.Sum([]byte(c.Icinga2.Endpoint))
-	idbTx := &sync.Mutex{}
 
 	progress := mpb.New()
 	for _, ht := range types {
@@ -287,7 +284,7 @@ func migrate(c *Config, idb *icingadb.DB, envId []byte) {
 	}
 
 	types.forEach(func(ht *historyType) {
-		ht.migrate(c, idb, envId, endpointId, idbTx, ht)
+		ht.migrate(c, idb, envId, endpointId, ht)
 	})
 
 	progress.Wait()
@@ -295,7 +292,7 @@ func migrate(c *Config, idb *icingadb.DB, envId []byte) {
 
 // migrate does the actual migration for one history type.
 func migrateOneType[IdoRow any](
-	c *Config, idb *icingadb.DB, envId []byte, endpointId [sha1.Size]byte, idbTx *sync.Mutex, ht *historyType,
+	c *Config, idb *icingadb.DB, envId []byte, endpointId [sha1.Size]byte, ht *historyType,
 	convertRows func(env string, envId, endpointId icingadbTypes.Binary,
 		selectCache func(dest interface{}, query string, args ...interface{}), ido *sqlx.Tx,
 		idoRows []IdoRow) (icingaDbInserts, icingaDbUpserts [][]any, checkpoint any),
@@ -359,13 +356,6 @@ func migrateOneType[IdoRow any](
 
 			// ... and insert them:
 
-			if idb.DriverName() == driver.MySQL {
-				// Avoid MySQL error 1205 (Lock wait timeout exceeded; try restarting transaction)
-				// due to concurrent transactions upsert the same table (history).
-				idbTx.Lock()
-				defer idbTx.Unlock()
-			}
-
 			tx, err := idb.Beginx()
 			if err != nil {
 				log.With("backend", "Icinga DB").Fatalf("%+v", errors.Wrap(err, "can't begin transaction"))
diff --git a/cmd/ido2icingadb/misc.go b/cmd/ido2icingadb/misc.go
index ff9cfeeb..19e17ba4 100644
--- a/cmd/ido2icingadb/misc.go
+++ b/cmd/ido2icingadb/misc.go
@@ -15,7 +15,6 @@ import (
 	"go.uber.org/zap"
 	"golang.org/x/sync/errgroup"
 	"strings"
-	"sync"
 	"time"
 )
 
@@ -201,8 +200,7 @@ type historyType struct {
 	// migrationQuery SELECTs source data for actual migration.
 	migrationQuery string
 	// migrate does the actual migration.
-	migrate func(c *Config, idb *icingadb.DB, envId []byte,
-		endpointId [sha1.Size]byte, idbTx *sync.Mutex, ht *historyType)
+	migrate func(c *Config, idb *icingadb.DB, envId []byte, endpointId [sha1.Size]byte, ht *historyType)
 
 	// cacheFile locates <name>.sqlite3.
 	cacheFile string
@@ -259,8 +257,8 @@ var types = historyTypes{
 		idoTable:       "icinga_commenthistory",
 		idoIdColumn:    "commenthistory_id",
 		migrationQuery: commentMigrationQuery,
-		migrate: func(c *Config, idb *icingadb.DB, envId []byte, endpId [20]byte, idbTx *sync.Mutex, ht *historyType) {
-			migrateOneType(c, idb, envId, endpId, idbTx, ht, convertCommentRows)
+		migrate: func(c *Config, idb *icingadb.DB, envId []byte, endpId [20]byte, ht *historyType) {
+			migrateOneType(c, idb, envId, endpId, ht, convertCommentRows)
 		},
 	},
 	{
@@ -268,8 +266,8 @@ var types = historyTypes{
 		idoTable:       "icinga_downtimehistory",
 		idoIdColumn:    "downtimehistory_id",
 		migrationQuery: downtimeMigrationQuery,
-		migrate: func(c *Config, idb *icingadb.DB, envId []byte, endpId [20]byte, idbTx *sync.Mutex, ht *historyType) {
-			migrateOneType(c, idb, envId, endpId, idbTx, ht, convertDowntimeRows)
+		migrate: func(c *Config, idb *icingadb.DB, envId []byte, endpId [20]byte, ht *historyType) {
+			migrateOneType(c, idb, envId, endpId, ht, convertDowntimeRows)
 		},
 	},
 	{
@@ -284,8 +282,8 @@ var types = historyTypes{
 			})
 		},
 		migrationQuery: flappingMigrationQuery,
-		migrate: func(c *Config, idb *icingadb.DB, envId []byte, endpId [20]byte, idbTx *sync.Mutex, ht *historyType) {
-			migrateOneType(c, idb, envId, endpId, idbTx, ht, convertFlappingRows)
+		migrate: func(c *Config, idb *icingadb.DB, envId []byte, endpId [20]byte, ht *historyType) {
+			migrateOneType(c, idb, envId, endpId, ht, convertFlappingRows)
 		},
 	},
 	{
@@ -300,8 +298,8 @@ var types = historyTypes{
 		},
 		cacheLimitQuery: "SELECT MAX(history_id) FROM previous_hard_state",
 		migrationQuery:  notificationMigrationQuery,
-		migrate: func(c *Config, idb *icingadb.DB, envId []byte, endpId [20]byte, idbTx *sync.Mutex, ht *historyType) {
-			migrateOneType(c, idb, envId, endpId, idbTx, ht, convertNotificationRows)
+		migrate: func(c *Config, idb *icingadb.DB, envId []byte, endpId [20]byte, ht *historyType) {
+			migrateOneType(c, idb, envId, endpId, ht, convertNotificationRows)
 		},
 	},
 	{
@@ -314,8 +312,8 @@ var types = historyTypes{
 		},
 		cacheLimitQuery: "SELECT MAX(history_id) FROM previous_hard_state",
 		migrationQuery:  stateMigrationQuery,
-		migrate: func(c *Config, idb *icingadb.DB, envId []byte, endpId [20]byte, idbTx *sync.Mutex, ht *historyType) {
-			migrateOneType(c, idb, envId, endpId, idbTx, ht, convertStateRows)
+		migrate: func(c *Config, idb *icingadb.DB, envId []byte, endpId [20]byte, ht *historyType) {
+			migrateOneType(c, idb, envId, endpId, ht, convertStateRows)
 		},
 	},
 }