diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 870ea25..1d1eb14 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,7 +23,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        scala: [2.12.13, 2.13.5]
+        scala: [2.12.13, 2.13.5, 3.0.0-RC3]
         java: [adopt@1.8]
     runs-on: ${{ matrix.os }}
     steps:
@@ -71,7 +71,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        scala: [2.13.5]
+        scala: [3.0.0-RC3]
         java: [adopt@1.8]
     runs-on: ${{ matrix.os }}
     steps:
@@ -117,6 +117,16 @@ jobs:
           tar xf targets.tar
           rm targets.tar
 
+      - name: Download target directories (3.0.0-RC3)
+        uses: actions/download-artifact@v2
+        with:
+          name: target-${{ matrix.os }}-3.0.0-RC3-${{ matrix.java }}
+
+      - name: Inflate target directories (3.0.0-RC3)
+        run: |
+          tar xf targets.tar
+          rm targets.tar
+
       - env:
           PGP_PASSPHRASE: ${{ secrets.PGP_PASSPHRASE }}
           PGP_SECRET: ${{ secrets.PGP_SECRET }}
diff --git a/.mergify.yml b/.mergify.yml
index 0c7db39..f2bed27 100644
--- a/.mergify.yml
+++ b/.mergify.yml
@@ -5,6 +5,7 @@ pull_request_rules:
       - author=scala-steward
       - check-success=Build and Test (ubuntu-latest, 2.12.13, adopt@1.8)
       - check-success=Build and Test (ubuntu-latest, 2.13.5, adopt@1.8)
+      - check-success=Build and Test (ubuntu-latest, 3.0.0-RC3, adopt@1.8)
     actions:
         merge:
             strict: true
diff --git a/asterisk/src/main/scala/simpleivr/asterisk/AgiIvrCommandInterpreter.scala b/asterisk/src/main/scala/simpleivr/asterisk/AgiIvrCommandInterpreter.scala
index f8dd05c..1619148 100644
--- a/asterisk/src/main/scala/simpleivr/asterisk/AgiIvrCommandInterpreter.scala
+++ b/asterisk/src/main/scala/simpleivr/asterisk/AgiIvrCommandInterpreter.scala
@@ -48,11 +48,13 @@ trait AgiIvrCommandInterpreter extends IOIvrCommandInterpreter {
 
   override def waitForSilence(ms: Int, repeat: Int = 1, timeoutSec: Option[Int] = None) = IO {
     channel.exec("WaitForSilence", s"$ms,$repeat" + timeoutSec.map("," + _).getOrElse(""))
+    ()
   }
 
   override def monitor(file: File) = IO {
     channel.exec("System", s"mkdir -p ${file.getParentFile.getAbsolutePath}")
     channel.exec("MixMonitor", file.getAbsolutePath)
+    ()
   }
 
   override def hangup = IO {
diff --git a/build.sbt b/build.sbt
index 82b5d4e..e7ffdf3 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,27 +1,33 @@
-ThisBuild / crossScalaVersions := Seq("2.12.13", "2.13.5")
+import _root_.io.github.nafg.scalacoptions.{ScalacOptions, options}
+
+ThisBuild / crossScalaVersions := Seq("2.12.13", "2.13.5", "3.0.0-RC3")
 ThisBuild / scalaVersion := (ThisBuild / crossScalaVersions).value.last
 ThisBuild / organization := "io.github.nafg.simpleivr"
 
 def ScalaTest = "org.scalatest" %% "scalatest" % "3.2.8"
 
-ThisBuild / scalacOptions ++= Seq(
-  "-deprecation",
-  "-feature",
-  "-unchecked",
-  "-explaintypes",
-  "-Xlint:_",
-  "-Ywarn-dead-code",
-  "-Ywarn-extra-implicit",
-  "-Ywarn-numeric-widen",
-  "-Ywarn-unused:_",
-  "-Ywarn-value-discard"
-)
-
 ThisBuild / scalacOptions ++=
-  (if (scalaVersion.value.startsWith("2.12."))
-    List("-language:higherKinds", "-Xfuture", "-Ypartial-unification")
-  else
-    Nil)
+  ScalacOptions.all(scalaVersion.value)(
+    (o: options.Common) =>
+      o.deprecation ++
+        o.feature ++
+        o.unchecked,
+    (o: options.V2) =>
+      o.explaintypes ++ Seq(
+        "-Xlint:_",
+        "-Ywarn-dead-code",
+        "-Ywarn-extra-implicit",
+        "-Ywarn-numeric-widen",
+        "-Ywarn-unused:_",
+        "-Ywarn-value-discard"
+      ),
+    (o: options.V2_12) =>
+      o.language("higherKinds") ++
+        o.Xfuture ++
+        o.YpartialUnification,
+    (o: options.V3) =>
+      o.explainTypes
+  )
 
 lazy val core = project
   .settings(
diff --git a/core/src/main/scala/simpleivr/Text2waveSpeakGenerator.scala b/core/src/main/scala/simpleivr/Text2waveSpeakGenerator.scala
index f5812f1..79abc71 100644
--- a/core/src/main/scala/simpleivr/Text2waveSpeakGenerator.scala
+++ b/core/src/main/scala/simpleivr/Text2waveSpeakGenerator.scala
@@ -26,6 +26,7 @@ object Text2waveSpeakGenerator extends SpeakGenerator {
               text2wave.waitFor()
               Source.fromInputStream(text2wave.getErrorStream).getLines() foreach println
               Files.copy(tmpFile, Channels.newOutputStream(writeChan))
+              ()
             }
           }
           .flatMap { either =>
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 6aa7036..69d2880 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -1,3 +1,4 @@
 addSbtPlugin("com.geirsson" % "sbt-ci-release" % "1.5.7")
 addSbtPlugin("com.codecommit" % "sbt-github-actions" % "0.10.1")
 libraryDependencies += "io.github.nafg.mergify" %% "mergify-writer" % "0.2.1"
+libraryDependencies += "io.github.nafg.scalac-options" %% "scalac-options" % "0.1.4"
diff --git a/testing/src/main/scala/simpleivr/testing/InteractionTestBase.scala b/testing/src/main/scala/simpleivr/testing/InteractionTestBase.scala
index bee8854..ce1f807 100644
--- a/testing/src/main/scala/simpleivr/testing/InteractionTestBase.scala
+++ b/testing/src/main/scala/simpleivr/testing/InteractionTestBase.scala
@@ -1,10 +1,10 @@
 package simpleivr.testing
 
-import scala.io.AnsiColor
-
-import cats.Id
+import cats.{Id, catsInstancesForId}
 import simpleivr.{IvrCommand, IvrStep}
 
+import scala.io.AnsiColor
+
 
 trait InteractionTestBase {
   case class RunWithConfig(error: String => Nothing, logIvrCommand: (IvrCommand[_], Any) => Unit = (_, _) => ()) {