diff --git a/build.sbt b/build.sbt
index 909654b1f..bea6cae21 100644
--- a/build.sbt
+++ b/build.sbt
@@ -435,6 +435,13 @@ lazy val utilScripted = (project in file("internal") / "util-scripted")
     name := "Util Scripted",
     libraryDependencies += scalaParsers,
     mimaSettings,
+    mimaBinaryIssueFilters ++= Vector(
+      exclude[DirectMissingMethodProblem](
+        "sbt.internal.scripted.BasicStatementHandler.initialState"
+      ),
+      exclude[IncompatibleResultTypeProblem]("sbt.internal.scripted.CommentHandler.initialState"),
+      exclude[IncompatibleResultTypeProblem]("sbt.internal.scripted.FileCommands.initialState"),
+    ),
   )
   .configure(addSbtIO)
 /* **** Intermediate-level Modules **** */
diff --git a/buildfile/src/main/scala/sbt/internal/Eval.scala b/buildfile/src/main/scala/sbt/internal/Eval.scala
index abf2f3fea..535fbb23f 100644
--- a/buildfile/src/main/scala/sbt/internal/Eval.scala
+++ b/buildfile/src/main/scala/sbt/internal/Eval.scala
@@ -107,8 +107,9 @@ class Eval(
         val header =
           imports.strings.mkString("\n") +
             s"""
-               |object $moduleName {
-               |  def $WrapValName${returnType} = {""".stripMargin
+               |@scala.annotation.nowarn("name=IllegalIdentifier")
+               |object `$moduleName` {
+               |  def `$WrapValName`${returnType} = {""".stripMargin
         val contents = s"""$header
           |$expression
           |  }
@@ -170,7 +171,8 @@ class Eval(
         val header =
           imports.strings.mkString("\n") +
             s"""
-               |object $moduleName {""".stripMargin
+               |@scala.annotation.nowarn("name=IllegalIdentifier")
+               |object `$moduleName` {""".stripMargin
         val contents =
           s"""$header
           |${definitions.map(_._1).mkString("\n")}
diff --git a/internal/util-scripted/src/main/scala/sbt/internal/scripted/StatementHandler.scala b/internal/util-scripted/src/main/scala/sbt/internal/scripted/StatementHandler.scala
index e0c9b968e..872ecbb1c 100644
--- a/internal/util-scripted/src/main/scala/sbt/internal/scripted/StatementHandler.scala
+++ b/internal/util-scripted/src/main/scala/sbt/internal/scripted/StatementHandler.scala
@@ -19,7 +19,7 @@ trait StatementHandler {
 
 trait BasicStatementHandler extends StatementHandler {
   final type State = Unit
-  final def initialState = ()
+  final def initialState: State = ()
 
   final def apply(command: String, arguments: List[String], state: Unit): Unit =
     apply(command, arguments)
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index f0de8b7e9..e4ec3dabd 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -3,7 +3,7 @@ import Keys.*
 
 object Dependencies {
   // WARNING: Please Scala update versions in PluginCross.scala too
-  val scala3 = "3.8.4"
+  val scala3 = "3.9.0-RC3"
   val scala212 = "2.12.21"
   val baseScalaVersion = scala3
   def nightlyVersion: Option[String] =