diff --git a/sbt/src/sbt-test/project/scala3-example-project/LICENSE b/sbt/src/sbt-test/project/scala3-example-project/LICENSE
new file mode 100644
index 000000000..728844ee3
--- /dev/null
+++ b/sbt/src/sbt-test/project/scala3-example-project/LICENSE
@@ -0,0 +1,25 @@
+Copyright (c) 2015 The dotty-example-project contributors.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+3. The name of the author may not be used to endorse or promote products
+   derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
diff --git a/sbt/src/sbt-test/project/scala3-example-project/README.md b/sbt/src/sbt-test/project/scala3-example-project/README.md
new file mode 100644
index 000000000..daa544226
--- /dev/null
+++ b/sbt/src/sbt-test/project/scala3-example-project/README.md
@@ -0,0 +1 @@
+Cut-n-pasted from https://github.com/scala/scala3-example-project/tree/353ccef820699f20eb012420a9deb28814481031
diff --git a/sbt/src/sbt-test/project/scala3-example-project/build.sbt b/sbt/src/sbt-test/project/scala3-example-project/build.sbt
new file mode 100644
index 000000000..14f3f6017
--- /dev/null
+++ b/sbt/src/sbt-test/project/scala3-example-project/build.sbt
@@ -0,0 +1 @@
+ThisBuild / scalaVersion := "3.0.0-M3"
diff --git a/sbt/src/sbt-test/project/scala3-example-project/src/main/scala-3/Main.scala b/sbt/src/sbt-test/project/scala3-example-project/src/main/scala-3/Main.scala
new file mode 100644
index 000000000..8a44ae4ef
--- /dev/null
+++ b/sbt/src/sbt-test/project/scala3-example-project/src/main/scala-3/Main.scala
@@ -0,0 +1,16 @@
+
+object Main {
+
+  def main(args: Array[String]): Unit = {
+
+    runExample("Trait Params")(TraitParams.test)
+
+  }
+
+  private def runExample(name: String)(f: => Unit) = {
+    println(Console.MAGENTA + s"$name example:" + Console.RESET)
+    f
+    println()
+  }
+
+}
diff --git a/sbt/src/sbt-test/project/scala3-example-project/src/main/scala-3/TraitParams.scala b/sbt/src/sbt-test/project/scala3-example-project/src/main/scala-3/TraitParams.scala
new file mode 100644
index 000000000..1ca8d7c42
--- /dev/null
+++ b/sbt/src/sbt-test/project/scala3-example-project/src/main/scala-3/TraitParams.scala
@@ -0,0 +1,21 @@
+/**
+ * Trait Parameters: https://dotty.epfl.ch/docs/reference/other-new-features/trait-parameters.html
+ */
+object TraitParams {
+
+  trait Base(val msg: String)
+  class A extends Base("Hello")
+  class B extends Base("Dotty!")
+
+  // Union types only exist in Dotty, so there's no chance that this will accidentally be compiled with Scala 2
+  private def printMessages(msgs: (A | B)*) = println(msgs.map(_.msg).mkString(" "))
+
+  def test: Unit = {
+
+    printMessages(new A, new B)
+
+    // Sanity check the classpath: this won't run if the dotty jar is not present.
+    val x: Int => Int = z => z
+    x(1)
+  }
+}
diff --git a/sbt/src/sbt-test/project/scala3-example-project/test b/sbt/src/sbt-test/project/scala3-example-project/test
new file mode 100644
index 000000000..62ea636c1
--- /dev/null
+++ b/sbt/src/sbt-test/project/scala3-example-project/test
@@ -0,0 +1 @@
+> run