diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9a7c9ee..6eea18d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -20,4 +20,4 @@ jobs:
         java-version: "${{ matrix.java }}"
         distribution: temurin
     - uses: coursier/cache-action@v6
-    - run: sbt -v scalafmtCheckAll scalafmtSbtCheck "^ test"
+    - run: sbt -v "+ scalafmtCheckAll" scalafmtSbtCheck "+ test"
diff --git a/.scalafmt.conf b/.scalafmt.conf
index 90e3ed3..6f91928 100644
--- a/.scalafmt.conf
+++ b/.scalafmt.conf
@@ -1,4 +1,5 @@
 runner.dialect = scala212source3
+project.layout = StandardConvention
 project.git = true
 maxColumn = 120
 rewrite.rules = [SortImports]
diff --git a/build.sbt b/build.sbt
index b05feca..60f24a5 100644
--- a/build.sbt
+++ b/build.sbt
@@ -8,6 +8,17 @@ name := "sbt-jshell"
 
 sbtPlugin := true
 
+crossScalaVersions += "3.3.4"
+
+pluginCrossBuild / sbtVersion := {
+  scalaBinaryVersion.value match {
+    case "2.12" =>
+      sbtVersion.value
+    case _ =>
+      "2.0.0-M2"
+  }
+}
+
 sbtPluginPublishLegacyMavenStyle := {
   sys.env.isDefinedAt("GITHUB_ACTION") || isSnapshot.value
 }
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 596a9a7..ba98cd1 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -1,4 +1,5 @@
 Compile / unmanagedSourceDirectories += baseDirectory.value.getParentFile / "src" / "main" / "scala"
+Compile / unmanagedSourceDirectories += baseDirectory.value.getParentFile / "src" / "main" / "scala-2"
 
 scalacOptions ++= Seq(
   "-deprecation",
diff --git a/src/main/scala-2/sbtjshell/JShellCompat.scala b/src/main/scala-2/sbtjshell/JShellCompat.scala
new file mode 100644
index 0000000..1296db1
--- /dev/null
+++ b/src/main/scala-2/sbtjshell/JShellCompat.scala
@@ -0,0 +1,20 @@
+package sbtjshell
+
+import sbt.{Configuration, Def, Task}
+import sbt.Keys.fullClasspath
+import java.io.File
+
+private[sbtjshell] trait JShellCompat { self: JShellPlugin.type =>
+  import self.autoImport.*
+
+  def jshellFullClasspath(c: Configuration): Def.Setting[?] = {
+    (c / jshell / fullClasspath) := {
+      (c / fullClasspath).value.filter(_.data.exists)
+    }
+  }
+
+  def jshellFullClasspathValue(c: Configuration): Def.Initialize[Task[Seq[File]]] =
+    Def.task(
+      (c / jshell / fullClasspath).value.map(_.data)
+    )
+}
diff --git a/src/main/scala-3/sbtjshell/JShellCompat.scala b/src/main/scala-3/sbtjshell/JShellCompat.scala
new file mode 100644
index 0000000..dd5a4e3
--- /dev/null
+++ b/src/main/scala-3/sbtjshell/JShellCompat.scala
@@ -0,0 +1,20 @@
+package sbtjshell
+
+import sbt.{Configuration, Def, given}
+import sbt.Keys.fullClasspath
+import sbt.Keys.fileConverter
+
+private[sbtjshell] trait JShellCompat { self: JShellPlugin.type =>
+
+  def jshellFullClasspath(c: Configuration): Def.Setting[?] = {
+    (c / autoImport.jshell / fullClasspath) := {
+      val converter = fileConverter.value
+      (c / fullClasspath).value.filter(x => converter.toPath(x.data).toFile.exists)
+    }
+  }
+
+  def jshellFullClasspathValue(c: Configuration) = Def.task {
+    val converter = fileConverter.value
+    (c / autoImport.jshell / fullClasspath).value.map(x => converter.toPath(x.data).toFile)
+  }
+}
diff --git a/src/main/scala/sbtjshell/JShellPlugin.scala b/src/main/scala/sbtjshell/JShellPlugin.scala
index aaf2483..f2ee9f7 100644
--- a/src/main/scala/sbtjshell/JShellPlugin.scala
+++ b/src/main/scala/sbtjshell/JShellPlugin.scala
@@ -2,12 +2,14 @@ package sbtjshell
 
 import javax.tools.Tool
 import java.util.ServiceLoader
-import sbt._
+// format: off
+import sbt.{given, *}
+// format: on
 import sbt.Keys._
 import sbt.complete.DefaultParsers._
 import scala.collection.JavaConverters._
 
-object JShellPlugin extends AutoPlugin {
+object JShellPlugin extends AutoPlugin with JShellCompat {
 
   object autoImport {
     val jshell = inputKey[Int]("invoke jshell")
@@ -30,14 +32,10 @@ object JShellPlugin extends AutoPlugin {
   override val projectSettings: Seq[Def.Setting[_]] = Def.settings(
     Seq(Compile, Test).flatMap { c =>
       Def.settings(
-        (c / jshell / fullClasspath) := {
-          (c / fullClasspath).value.filter(_.data.exists)
-        },
+        jshellFullClasspath(c),
         (c / jshell) := {
           val args = spaceDelimited("<arg>").parsed.toList
-          val path = (c / jshell / fullClasspath).value
-            .map(_.data.getCanonicalPath)
-            .mkString(System.getProperty("path.separator"))
+          val path = jshellFullClasspathValue(c).value.map(_.getCanonicalPath).mkString(java.io.File.pathSeparator)
 
           IO.withTemporaryFile("jshell-startup", ".jsh") { temp =>
             val startup = (c / jshell / initialCommands).?.value match {