diff --git a/build.sbt b/build.sbt
index 4b71318ee..b5f6d6d4c 100644
--- a/build.sbt
+++ b/build.sbt
@@ -7,6 +7,8 @@ val _ = {
   sys.props += ("line.separator" -> "\n")
 }
 
+ThisBuild / Test / classLoaderLayeringStrategy := ClassLoaderLayeringStrategy.Flat
+
 def commonSettings: Seq[Setting[_]] = Def.settings(
   scalaVersion := scala212,
   // publishArtifact in packageDoc := false,