diff --git a/build.sbt b/build.sbt
index 8e2f18f..2a4b791 100755
--- a/build.sbt
+++ b/build.sbt
@@ -72,7 +72,6 @@ lazy val sbtSonatype =
       testFrameworks += new TestFramework("wvlet.airspec.Framework"),
       buildInfoKeys    := Seq[BuildInfoKey](name, version, scalaVersion, sbtVersion),
       buildInfoPackage := "org.xerial.sbt.sonatype",
-      scalacOptions ++= Seq("-nowarn"),
       scalacOptions += {
         scalaBinaryVersion.value match {
           case "2.12" =>
diff --git a/src/main/scala/xerial/sbt/sonatype/SonatypeClient.scala b/src/main/scala/xerial/sbt/sonatype/SonatypeClient.scala
index ede6dba..80ccfa0 100644
--- a/src/main/scala/xerial/sbt/sonatype/SonatypeClient.scala
+++ b/src/main/scala/xerial/sbt/sonatype/SonatypeClient.scala
@@ -8,6 +8,7 @@ import org.apache.http.impl.client.BasicCredentialsProvider
 import org.sonatype.spice.zapper.client.hc4.Hc4ClientBuilder
 import org.sonatype.spice.zapper.ParametersBuilder
 import sbt.librarymanagement.ivy.Credentials
+import scala.annotation.nowarn
 import scala.concurrent.duration.Duration
 import wvlet.airframe.control.{Control, ResultClass, Retry}
 import wvlet.airframe.http.*
@@ -36,6 +37,7 @@ class SonatypeClient(
 
   private val pathPrefix = repoUri.getPath
 
+  @nowarn("msg=URLConnectionClientBackend")
   private[sonatype] val clientConfig = {
     Http.client
       .withName("sonatype-client")