diff --git a/build.sc b/build.sc
index 7f2ad03..86abe33 100644
--- a/build.sc
+++ b/build.sc
@@ -10,7 +10,7 @@ import mill.bsp._
 
 object playground extends SbtModule with ScalafmtModule { m =>
   val useChisel3 = false
-  override def millSourcePath = os.pwd
+  override def millSourcePath = os.pwd / "src"
   override def scalaVersion = "2.13.12"
   override def scalacOptions = Seq(
     "-language:reflectiveCalls",
@@ -19,7 +19,7 @@ object playground extends SbtModule with ScalafmtModule { m =>
     "-Xcheckinit"
   )
   override def sources = T.sources {
-    super.sources() ++ Seq(PathRef(millSourcePath / "playground" / "src" ))
+    super.sources() ++ Seq(PathRef(millSourcePath / "main"))
   }
   override def ivyDeps = Agg(
     if (useChisel3) ivy"edu.berkeley.cs::chisel3:3.6.0" else
@@ -31,7 +31,7 @@ object playground extends SbtModule with ScalafmtModule { m =>
   )
   object test extends SbtModuleTests with TestModule.ScalaTest {
     override def sources = T.sources {
-      super.sources() ++ Seq(PathRef(millSourcePath / "playground" / "test" / "src"))
+      super.sources() ++ Seq(PathRef(millSourcePath / "test"))
     }
     override def ivyDeps = super.ivyDeps() ++ Agg(
       if (useChisel3) ivy"edu.berkeley.cs::chiseltest:0.6.0" else
diff --git a/playground/src/DecoupledGCD.scala b/src/main/DecoupledGCD.scala
similarity index 100%
rename from playground/src/DecoupledGCD.scala
rename to src/main/DecoupledGCD.scala
diff --git a/playground/src/Elaborate.scala b/src/main/Elaborate.scala
similarity index 100%
rename from playground/src/Elaborate.scala
rename to src/main/Elaborate.scala
diff --git a/playground/src/GCD.scala b/src/main/GCD.scala
similarity index 100%
rename from playground/src/GCD.scala
rename to src/main/GCD.scala
diff --git a/playground/test/src/GCDSpec.scala b/src/test/GCDSpec.scala
similarity index 100%
rename from playground/test/src/GCDSpec.scala
rename to src/test/GCDSpec.scala