diff --git a/build.sbt b/build.sbt
index ad3f7f50da..77217d4627 100644
--- a/build.sbt
+++ b/build.sbt
@@ -128,7 +128,7 @@ val play2JsonVersion: Option[(Long, Long)] => String = {
   case Some((2, 11)) => "2.7.4"
   case _             => "2.9.2"
 }
-val playJsonVersion = "3.0.0"
+val playJsonVersion = "3.0.2"
 val catsEffect_3_version = "3.5.1"
 val fs2_3_version = "3.7.0"
 
@@ -950,10 +950,10 @@ lazy val playJson = (projectMatrix in file("json/play-json"))
     scalaTest
   )
   .jvmPlatform(
-    scalaVersions = scala2alive,
+    scalaVersions = scala2alive ++ scala3,
     settings = commonJvmSettings
   )
-  .jsPlatform(scalaVersions = scala2alive, settings = commonJsSettings)
+  .jsPlatform(scalaVersions = scala2alive ++ scala3, settings = commonJsSettings)
   .dependsOn(core, jsonCommon)
 
 lazy val prometheusBackend = (projectMatrix in file("observability/prometheus-backend"))
diff --git a/json/play-json/src/test/scala/sttp/client3/PlayJsonTests.scala b/json/play-json/src/test/scala/sttp/client3/PlayJsonTests.scala
index 269458eacc..fdb47354c7 100644
--- a/json/play-json/src/test/scala/sttp/client3/PlayJsonTests.scala
+++ b/json/play-json/src/test/scala/sttp/client3/PlayJsonTests.scala
@@ -79,7 +79,7 @@ class PlayJsonTests extends AnyFlatSpec with Matchers with EitherValues {
     val encoded = extractBody(basicRequest.body(outer))
     val decoded = runJsonResponseAs(asJson[Outer])(encoded)
 
-    decoded.right.value shouldBe outer
+    decoded.value shouldBe outer
   }
 
   it should "set the content type" in {
@@ -136,7 +136,7 @@ class PlayJsonTests extends AnyFlatSpec with Matchers with EitherValues {
 
   def runJsonResponseAs[A](responseAs: ResponseAs[A, Nothing]): String => A =
     responseAs match {
-      case responseAs: MappedResponseAs[_, A, Nothing] =>
+      case responseAs: MappedResponseAs[_, _, _] =>
         responseAs.raw match {
           case ResponseAsByteArray =>
             s => responseAs.g(s.getBytes(Utf8), ResponseMetadata(StatusCode.Ok, "", Nil))