fixup

Author: SethTisue

build.sbt

@@ -65,7 +65,14 @@ lazy val compat = new MultiScalaCrossProject(
       scalacOptions ++= Seq("-feature", "-language:higherKinds", "-language:implicitConversions"),
       // we need to force Scala 3 to use the latest Scala 2 stdlib, otherwise
       // we might get test failures if there are behavior changes in latest Scala 2 stdlib
-      dependencyOverrides += "org.scala-lang" % "scala-library" % scala213,
+      dependencyOverrides ++= {
+        CrossVersion.partialVersion(scalaVersion.value) match {
+          case Some((3, _)) =>
+            Seq("org.scala-lang" % "scala-library" % scala213)
+          case _ =>
+            Seq()
+        }
+      },
       Compile / unmanagedSourceDirectories += {
         val sharedSourceDir = (ThisBuild / baseDirectory).value / "compat/src/main"
         CrossVersion.partialVersion(scalaVersion.value) match {