diff --git a/.git-blame-ignore-revs b/.git-blame-ignore-revs
index 285ed6f4..aead1172 100644
--- a/.git-blame-ignore-revs
+++ b/.git-blame-ignore-revs
@@ -1,2 +1,5 @@
 # Scala Steward: Reformat with scalafmt 3.9.9
 424ec59eb4865feb383ca53b4278dfb8b9b6c36c
+
+# Scala Steward: Reformat with scalafmt 3.10.3
+d8af028d2cd271ab7f3adec9842f07cce86a2ac3
diff --git a/.scalafmt.conf b/.scalafmt.conf
index 8ef32eb0..d30b0537 100644
--- a/.scalafmt.conf
+++ b/.scalafmt.conf
@@ -1,4 +1,4 @@
-version = 3.9.10
+version = 3.10.3
 project.layout = StandardConvention
 runner.dialect = scala3
 maxColumn = 100
diff --git a/msgpack-core/src/test/scala/org/msgpack/core/MessagePackSpec.scala b/msgpack-core/src/test/scala/org/msgpack/core/MessagePackSpec.scala
index 135c4921..21080f65 100644
--- a/msgpack-core/src/test/scala/org/msgpack/core/MessagePackSpec.scala
+++ b/msgpack-core/src/test/scala/org/msgpack/core/MessagePackSpec.scala
@@ -16,7 +16,8 @@
 package org.msgpack.core
 
 import wvlet.log.LogLevel
-import wvlet.log.io.{TimeReport, Timer}
+import wvlet.log.io.TimeReport
+import wvlet.log.io.Timer
 
 import java.io.ByteArrayOutputStream
 
diff --git a/msgpack-core/src/test/scala/org/msgpack/core/MessagePackTest.scala b/msgpack-core/src/test/scala/org/msgpack/core/MessagePackTest.scala
index b5541393..16236c65 100644
--- a/msgpack-core/src/test/scala/org/msgpack/core/MessagePackTest.scala
+++ b/msgpack-core/src/test/scala/org/msgpack/core/MessagePackTest.scala
@@ -15,18 +15,23 @@
 //
 package org.msgpack.core
 
-import org.msgpack.core.MessagePack.{Code, PackerConfig, UnpackerConfig}
+import org.msgpack.core.MessagePack.Code
+import org.msgpack.core.MessagePack.PackerConfig
+import org.msgpack.core.MessagePack.UnpackerConfig
 import org.msgpack.core.MessagePackSpec.toHex
-import org.msgpack.value.{Value, Variable}
+import org.msgpack.value.Value
+import org.msgpack.value.Variable
 import org.scalacheck.Prop.propBoolean
-import org.scalacheck.{Arbitrary, Gen}
+import org.scalacheck.Arbitrary
+import org.scalacheck.Gen
 import wvlet.airspec.AirSpec
 import wvlet.airspec.spi.PropertyCheck
 
 import java.io.ByteArrayOutputStream
 import java.math.BigInteger
 import java.nio.CharBuffer
-import java.nio.charset.{CodingErrorAction, UnmappableCharacterException}
+import java.nio.charset.CodingErrorAction
+import java.nio.charset.UnmappableCharacterException
 import java.time.Instant
 import scala.util.Random
 
diff --git a/msgpack-core/src/test/scala/org/msgpack/core/MessagePackerTest.scala b/msgpack-core/src/test/scala/org/msgpack/core/MessagePackerTest.scala
index 7ff5d82e..e31853ab 100644
--- a/msgpack-core/src/test/scala/org/msgpack/core/MessagePackerTest.scala
+++ b/msgpack-core/src/test/scala/org/msgpack/core/MessagePackerTest.scala
@@ -16,12 +16,16 @@
 package org.msgpack.core
 
 import org.msgpack.core.MessagePack.PackerConfig
-import org.msgpack.core.buffer.{ChannelBufferOutput, OutputStreamBufferOutput}
+import org.msgpack.core.buffer.ChannelBufferOutput
+import org.msgpack.core.buffer.OutputStreamBufferOutput
 import org.msgpack.value.ValueFactory
 import wvlet.airspec.AirSpec
 import wvlet.log.io.IOUtil.withResource
 
-import java.io.{ByteArrayOutputStream, File, FileInputStream, FileOutputStream}
+import java.io.ByteArrayOutputStream
+import java.io.File
+import java.io.FileInputStream
+import java.io.FileOutputStream
 import scala.util.Random
 
 /**
diff --git a/msgpack-core/src/test/scala/org/msgpack/core/MessageUnpackerTest.scala b/msgpack-core/src/test/scala/org/msgpack/core/MessageUnpackerTest.scala
index adab4708..bf43591a 100644
--- a/msgpack-core/src/test/scala/org/msgpack/core/MessageUnpackerTest.scala
+++ b/msgpack-core/src/test/scala/org/msgpack/core/MessageUnpackerTest.scala
@@ -15,7 +15,8 @@
 //
 package org.msgpack.core
 
-import org.msgpack.core.MessagePackSpec.{createMessagePackData, toHex}
+import org.msgpack.core.MessagePackSpec.createMessagePackData
+import org.msgpack.core.MessagePackSpec.toHex
 import org.msgpack.core.buffer.*
 import org.msgpack.value.ValueType
 import wvlet.airspec.AirSpec
@@ -67,8 +68,8 @@ class MessageUnpackerTest extends AirSpec with Benchmark:
 
   private val intSeq =
     (
-      for (i <- 0 until 100)
-        yield Random.nextInt()
+      for i <- 0 until 100
+      yield Random.nextInt()
     ).toArray[Int]
 
   private def testData2: Array[Byte] =
diff --git a/msgpack-core/src/test/scala/org/msgpack/core/buffer/MessageBufferInputTest.scala b/msgpack-core/src/test/scala/org/msgpack/core/buffer/MessageBufferInputTest.scala
index 5e6c1f96..0465aa69 100644
--- a/msgpack-core/src/test/scala/org/msgpack/core/buffer/MessageBufferInputTest.scala
+++ b/msgpack-core/src/test/scala/org/msgpack/core/buffer/MessageBufferInputTest.scala
@@ -22,9 +22,13 @@ import wvlet.log.io.IOUtil.withResource
 import java.io.*
 import java.net.InetSocketAddress
 import java.nio.ByteBuffer
-import java.nio.channels.{ServerSocketChannel, SocketChannel}
-import java.util.concurrent.{Callable, Executors, TimeUnit}
-import java.util.zip.{GZIPInputStream, GZIPOutputStream}
+import java.nio.channels.ServerSocketChannel
+import java.nio.channels.SocketChannel
+import java.util.concurrent.Callable
+import java.util.concurrent.Executors
+import java.util.concurrent.TimeUnit
+import java.util.zip.GZIPInputStream
+import java.util.zip.GZIPOutputStream
 import scala.util.Random
 
 class MessageBufferInputTest extends AirSpec:
diff --git a/msgpack-core/src/test/scala/org/msgpack/value/ValueTypeTest.scala b/msgpack-core/src/test/scala/org/msgpack/value/ValueTypeTest.scala
index 7b992f28..53707c99 100644
--- a/msgpack-core/src/test/scala/org/msgpack/value/ValueTypeTest.scala
+++ b/msgpack-core/src/test/scala/org/msgpack/value/ValueTypeTest.scala
@@ -16,7 +16,8 @@
 package org.msgpack.value
 
 import org.msgpack.core.MessagePack.Code.*
-import org.msgpack.core.{MessageFormat, MessageFormatException}
+import org.msgpack.core.MessageFormat
+import org.msgpack.core.MessageFormatException
 import wvlet.airspec.AirSpec
 
 /**
diff --git a/msgpack-core/src/test/scala/org/msgpack/value/VariableTest.scala b/msgpack-core/src/test/scala/org/msgpack/value/VariableTest.scala
index 2f3cbf9c..d4754e83 100644
--- a/msgpack-core/src/test/scala/org/msgpack/value/VariableTest.scala
+++ b/msgpack-core/src/test/scala/org/msgpack/value/VariableTest.scala
@@ -15,7 +15,9 @@
 //
 package org.msgpack.value
 
-import org.msgpack.core.{MessagePack, MessagePacker, MessageTypeCastException}
+import org.msgpack.core.MessagePack
+import org.msgpack.core.MessagePacker
+import org.msgpack.core.MessageTypeCastException
 import wvlet.airspec.AirSpec
 import wvlet.airspec.spi.PropertyCheck