diff --git a/src/test/scala/TopMain.scala b/src/test/scala/TopMain.scala
index 583fa532..8c717898 100644
--- a/src/test/scala/TopMain.scala
+++ b/src/test/scala/TopMain.scala
@@ -92,5 +92,6 @@ object TopMain extends App {
   (new ChiselStage).execute(newArgs, Seq(generator) ++ firtoolOptions
     :+ CIRCTTargetAnnotation(CIRCTTarget.SystemVerilog)
     :+ FirtoolOption("--disable-annotation-unknown")
+    :+ FirtoolOption("--default-layer-specialization=enable")
   )
 }
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