diff --git a/packages/mongo/src/index.ts b/packages/mongo/src/index.ts
index 8c711642..dcea6880 100644
--- a/packages/mongo/src/index.ts
+++ b/packages/mongo/src/index.ts
@@ -15,6 +15,7 @@ export class MongoDriver extends Driver<MongoDriver.Config> {
 
   private session?: ClientSession
   private _createTasks: Dict<Promise<void>> = {}
+  private _ensureTask: Dict<Promise<void>> = {}
 
   private connectionStringFromConfig() {
     const {
@@ -349,15 +350,27 @@ export class MongoDriver extends Driver<MongoDriver.Config> {
     const { primary, autoInc } = model
     if (typeof primary === 'string' && autoInc && model.fields[primary]?.type !== 'primary') {
       const missing = data.filter(item => !(primary in item))
-      if (!missing.length) return
-      const doc = await this.db.collection('_fields').findOneAndUpdate(
-        { table, field: primary },
-        { $inc: { autoInc: missing.length } },
-        { session: this.session, upsert: true },
-      )
-      for (let i = 1; i <= missing.length; i++) {
-        missing[i - 1][primary] = (doc!.autoInc ?? 0) + i
-      }
+      const lastTask = Promise.resolve(this._ensureTask[table]).catch(noop)
+      return this._ensureTask[table] = lastTask.then(async () => {
+        if (!missing.length) {
+          return this.db.collection('_fields').updateOne(
+            { table, field: primary },
+            [{ $set: { autoInc: { $max: ['$autoInc', Math.max(...data.map(x => x[primary]))] } } }],
+            { session: this.session, upsert: true },
+          ).then(noop)
+        }
+        const doc = await this.db.collection('_fields').findOne({ table, field: primary }, { session: this.session })
+        const exists = data.filter(item => item[primary] > (doc?.autoInc ?? 0)).map(x => x[primary]).sort()
+        let j = 0
+        for (let i = 1; i <= missing.length; i++) {
+          while (exists[j] && (doc?.autoInc ?? 0) + i + j >= exists[j]) j++
+          missing[i - 1][primary] = (doc?.autoInc ?? 0) + i + j
+        }
+        await this.db.collection('_fields').updateOne(
+          { table, field: primary },
+          { $set: { autoInc: (doc?.autoInc ?? 0) + missing.length + j } },
+          { session: this.session, upsert: true })
+      })
     }
   }
 
diff --git a/packages/postgres/src/index.ts b/packages/postgres/src/index.ts
index f3e62fd2..c1728421 100644
--- a/packages/postgres/src/index.ts
+++ b/packages/postgres/src/index.ts
@@ -1,6 +1,6 @@
 import postgres from 'postgres'
 import { Dict, difference, isNullable, makeArray, pick } from 'cosmokit'
-import { Driver, Eval, executeUpdate, Field, Selection, z } from 'minato'
+import { Driver, Eval, executeUpdate, Field, randomId, Selection, z } from 'minato'
 import { isBracketed } from '@minatojs/sql-utils'
 import { formatTime, PostgresBuilder } from './builder'
 
@@ -393,10 +393,17 @@ export class PostgresDriver extends Driver<PostgresDriver.Config> {
     const { table, model } = sel
     const builder = new PostgresBuilder(sel.tables)
     const formatted = builder.dump(model, data)
+
     const keys = Object.keys(formatted)
     const [row] = await this.query([
       `INSERT INTO ${builder.escapeId(table)} (${keys.map(builder.escapeId).join(', ')})`,
-      `VALUES (${keys.map(key => builder.escape(formatted[key])).join(', ')})`,
+      `VALUES (${keys.map(key => {
+        if (model.autoInc && key === model.primary) {
+          return `(select ${formatted[key]} from (select setval(pg_get_serial_sequence(${builder.escapeKey(table)}, ${builder.escapeKey(key)}),
+          greatest(nextval(pg_get_serial_sequence(${builder.escapeKey(table)}, ${builder.escapeKey(key)}))-1, ${formatted[key]}))) ${randomId()})`
+        }
+        return builder.escape(formatted[key])
+      }).join(', ')})`,
       `RETURNING *`,
     ].join(' '))
     return builder.load(model, row)
@@ -436,7 +443,11 @@ export class PostgresDriver extends Driver<PostgresDriver.Config> {
     const formatValues = (table: string, data: object, keys: readonly string[]) => {
       return keys.map((key) => {
         const field = this.database.tables[table]?.fields[key]
-        if (model.autoInc && model.primary === key && !data[key]) return 'default'
+        if (model.autoInc && model.primary === key) {
+          return data[key] ? `(select ${data[key]} from (select setval(pg_get_serial_sequence(${builder.escapeKey(table)}, ${builder.escapeKey(key)}),
+            greatest(nextval(pg_get_serial_sequence(${builder.escapeKey(table)}, ${builder.escapeKey(key)}))-1, ${data[key]}))) ${randomId()})`
+            : 'default'
+        }
         return builder.escape(data[key], field)
       }).join(', ')
     }