diff --git a/build.mill b/build.mill
index 6b5b08d..a4ef52d 100644
--- a/build.mill
+++ b/build.mill
@@ -15,7 +15,7 @@ import mill.bsp._
 
 object %NAME% extends SbtModule { m =>
   override def millSourcePath = super.millSourcePath / os.up
-  override def scalaVersion = "2.13.15"
+  override def scalaVersion = "2.13.16"
   override def scalacOptions = Seq(
     "-language:reflectiveCalls",
     "-deprecation",
@@ -23,14 +23,14 @@ object %NAME% extends SbtModule { m =>
     "-Xcheckinit",
   )
   override def ivyDeps = Agg(
-    ivy"org.chipsalliance::chisel:6.6.0",
+    ivy"org.chipsalliance::chisel:7.0.0-RC1",
   )
   override def scalacPluginIvyDeps = Agg(
-    ivy"org.chipsalliance:::chisel-plugin:6.6.0",
+    ivy"org.chipsalliance:::chisel-plugin:7.0.0-RC1",
   )
   object test extends SbtTests with TestModule.ScalaTest {
     override def ivyDeps = m.ivyDeps() ++ Agg(
-      ivy"org.scalatest::scalatest::3.2.16"
+      ivy"org.scalatest::scalatest::3.2.19"
     )
   }
 }
diff --git a/build.sbt b/build.sbt
index f8cc2af..ad43737 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,17 +1,17 @@
 // See README.md for license details.
 
-ThisBuild / scalaVersion     := "2.13.15"
+ThisBuild / scalaVersion     := "2.13.16"
 ThisBuild / version          := "0.1.0"
 ThisBuild / organization     := "%ORGANIZATION%"
 
-val chiselVersion = "6.6.0"
+val chiselVersion = "7.0.0-RC1"
 
 lazy val root = (project in file("."))
   .settings(
     name := "%NAME%",
     libraryDependencies ++= Seq(
       "org.chipsalliance" %% "chisel" % chiselVersion,
-      "org.scalatest" %% "scalatest" % "3.2.16" % "test",
+      "org.scalatest" %% "scalatest" % "3.2.19" % "test",
     ),
     scalacOptions ++= Seq(
       "-language:reflectiveCalls",
diff --git a/src/main/scala/gcd/GCD.scala b/src/main/scala/gcd/GCD.scala
index 42c5e80..e6690d2 100644
--- a/src/main/scala/gcd/GCD.scala
+++ b/src/main/scala/gcd/GCD.scala
@@ -41,6 +41,6 @@ class GCD extends Module {
 object GCD extends App {
   ChiselStage.emitSystemVerilogFile(
     new GCD,
-    firtoolOpts = Array("-disable-all-randomization", "-strip-debug-info")
+    firtoolOpts = Array("-disable-all-randomization", "-strip-debug-info", "-default-layer-specialization=enable")
   )
 }
diff --git a/src/test/scala/gcd/GCDSpec.scala b/src/test/scala/gcd/GCDSpec.scala
index e8c7ce8..0ce4abd 100644
--- a/src/test/scala/gcd/GCDSpec.scala
+++ b/src/test/scala/gcd/GCDSpec.scala
@@ -4,7 +4,7 @@ package gcd
 
 import chisel3._
 import chisel3.experimental.BundleLiterals._
-import chisel3.simulator.EphemeralSimulator._
+import chisel3.simulator.scalatest.ChiselSim
 import org.scalatest.freespec.AnyFreeSpec
 import org.scalatest.matchers.must.Matchers
 
@@ -23,7 +23,7 @@ import org.scalatest.matchers.must.Matchers
   * mill %NAME%.test.testOnly gcd.GCDSpec
   * }}}
   */
-class GCDSpec extends AnyFreeSpec with Matchers {
+class GCDSpec extends AnyFreeSpec with Matchers with ChiselSim {
 
   "Gcd should calculate proper greatest common denominator" in {
     simulate(new DecoupledGcd(16)) { dut =>