diff --git a/build.sbt b/build.sbt
index 82a522f7a7..eabd1c5a5e 100644
--- a/build.sbt
+++ b/build.sbt
@@ -312,6 +312,8 @@ val Specs2Version = "4.20.0"
 val ScalaCheckVersion = "1.17.0"
 val DisciplineVersion = "1.4.0"
 val CoopVersion = "1.2.0"
+val MUnitVersion = "1.0.0-M8"
+val DisciplineMUnitVersion = "2.0.0-M3"
 
 val MacrotaskExecutorVersion = "1.1.1"
 
@@ -393,8 +395,7 @@ lazy val kernel = crossProject(JSPlatform, JVMPlatform, NativePlatform)
   .settings(
     name := "cats-effect-kernel",
     libraryDependencies ++= Seq(
-      "org.typelevel" %%% "cats-core" % CatsVersion,
-      "org.specs2" %%% "specs2-core" % Specs2Version % Test
+      "org.typelevel" %%% "cats-core" % CatsVersion
     ),
     mimaBinaryIssueFilters ++= Seq(
       ProblemFilters.exclude[MissingClassProblem]("cats.effect.kernel.Ref$SyncRef"),
@@ -451,7 +452,7 @@ lazy val laws = crossProject(JSPlatform, JVMPlatform, NativePlatform)
     name := "cats-effect-laws",
     libraryDependencies ++= Seq(
       "org.typelevel" %%% "cats-laws" % CatsVersion,
-      "org.typelevel" %%% "discipline-specs2" % DisciplineVersion % Test)
+      "org.typelevel" %%% "discipline-munit" % DisciplineMUnitVersion % Test)
   )
   .disablePlugins(JCStressPlugin)
 
diff --git a/kernel/shared/src/test/scala/cats/effect/kernel/SyntaxSpec.scala b/kernel/shared/src/test/scala/cats/effect/kernel/SyntaxSuite.scala
similarity index 97%
rename from kernel/shared/src/test/scala/cats/effect/kernel/SyntaxSpec.scala
rename to kernel/shared/src/test/scala/cats/effect/kernel/SyntaxSuite.scala
index 2563ffbefd..d3c8c6a180 100644
--- a/kernel/shared/src/test/scala/cats/effect/kernel/SyntaxSpec.scala
+++ b/kernel/shared/src/test/scala/cats/effect/kernel/SyntaxSuite.scala
@@ -18,14 +18,10 @@ package cats.effect.kernel
 
 import cats.implicits._
 
-import org.specs2.mutable.Specification
-
 import scala.concurrent.ExecutionContext
 import scala.concurrent.duration.{Duration, FiniteDuration}
 
-class SyntaxSpec extends Specification {
-
-  "kernel syntax" >> ok
+class SyntaxSuite {
 
   def concurrentForwarder[F[_]: Concurrent] =
     Concurrent[F]
diff --git a/laws/shared/src/test/scala/cats/effect/BaseSpec.scala b/laws/shared/src/test/scala/cats/effect/BaseSuite.scala
similarity index 99%
rename from laws/shared/src/test/scala/cats/effect/BaseSpec.scala
rename to laws/shared/src/test/scala/cats/effect/BaseSuite.scala
index ec3e295e3a..fb8a9c0baa 100644
--- a/laws/shared/src/test/scala/cats/effect/BaseSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/BaseSuite.scala
@@ -27,7 +27,7 @@ import org.scalacheck.{Arbitrary, Gen, Prop}
 import org.scalacheck.util.Pretty
 
 // A dumping ground for random helpers for property tests
-private[effect] trait BaseSpec {
+private[effect] trait BaseSuite {
 
   implicit def kleisliEq[F[_], A, B](implicit ev: Eq[A => F[B]]): Eq[Kleisli[F, A, B]] =
     Eq.by[Kleisli[F, A, B], A => F[B]](_.run)
diff --git a/laws/shared/src/test/scala/cats/effect/kernel/OutcomeSpec.scala b/laws/shared/src/test/scala/cats/effect/kernel/OutcomeSuite.scala
similarity index 91%
rename from laws/shared/src/test/scala/cats/effect/kernel/OutcomeSpec.scala
rename to laws/shared/src/test/scala/cats/effect/kernel/OutcomeSuite.scala
index 08f27092bf..6dcf0ec468 100644
--- a/laws/shared/src/test/scala/cats/effect/kernel/OutcomeSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/kernel/OutcomeSuite.scala
@@ -22,10 +22,10 @@ import cats.effect.kernel.testkit.OutcomeGenerators
 import cats.laws.discipline.{ApplicativeErrorTests, MonadErrorTests}
 
 import org.scalacheck.{Arbitrary, Cogen}
-import org.specs2.mutable.Specification
-import org.typelevel.discipline.specs2.mutable.Discipline
 
-class OutcomeSpec extends Specification with Discipline {
+import munit.DisciplineSuite
+
+class OutcomeSuite extends DisciplineSuite {
   import OutcomeGenerators._
 
   {
diff --git a/laws/shared/src/test/scala/cats/effect/laws/ClockSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/ClockSuite.scala
similarity index 83%
rename from laws/shared/src/test/scala/cats/effect/laws/ClockSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/ClockSuite.scala
index 0008bc8e16..8707fca1d1 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/ClockSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/ClockSuite.scala
@@ -20,10 +20,9 @@ package laws
 import cats.data.ContT
 import cats.effect.kernel.testkit.freeEval._
 
-import org.specs2.mutable.Specification
-import org.typelevel.discipline.specs2.mutable.Discipline
+import munit.DisciplineSuite
 
-class ClockSpec extends Specification with Discipline with BaseSpec {
+class ClockSuite extends DisciplineSuite with BaseSuite {
 
   // we only need to test the ones that *aren't* also Sync
   checkAll("ContT[FreeEitherSync, Int, *]", ClockTests[ContT[FreeEitherSync, Int, *]].clock)
diff --git a/laws/shared/src/test/scala/cats/effect/laws/EitherTFreeSyncSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/EitherTFreeSyncSuite.scala
similarity index 89%
rename from laws/shared/src/test/scala/cats/effect/laws/EitherTFreeSyncSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/EitherTFreeSyncSuite.scala
index 5968c63467..64c6492349 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/EitherTFreeSyncSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/EitherTFreeSyncSuite.scala
@@ -24,13 +24,11 @@ import cats.effect.kernel.testkit.freeEval.{syncForFreeT, FreeEitherSync}
 import cats.free.FreeT
 import cats.laws.discipline.arbitrary._
 
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
+import munit.DisciplineSuite
 
-class EitherTFreeSyncSpec
-    extends Specification
-    with Discipline
-    with BaseSpec
+class EitherTFreeSyncSuite
+    extends DisciplineSuite
+    with BaseSuite
     with LowPriorityImplicits {
   import FreeSyncGenerators._
   import SyncTypeGenerators._
diff --git a/laws/shared/src/test/scala/cats/effect/laws/EitherTPureConcSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/EitherTPureConcSuite.scala
similarity index 89%
rename from laws/shared/src/test/scala/cats/effect/laws/EitherTPureConcSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/EitherTPureConcSuite.scala
index 9e38a3fd87..90b94ed7b9 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/EitherTPureConcSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/EitherTPureConcSuite.scala
@@ -24,12 +24,12 @@ import cats.effect.kernel.testkit.pure._
 import cats.laws.discipline.arbitrary._
 
 import org.scalacheck.Prop
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
 
 import scala.concurrent.duration._
 
-class EitherTPureConcSpec extends Specification with Discipline with BaseSpec {
+import munit.DisciplineSuite
+
+class EitherTPureConcSuite extends DisciplineSuite with BaseSuite {
   import PureConcGenerators._
   import OutcomeGenerators._
 
diff --git a/laws/shared/src/test/scala/cats/effect/laws/FreeSyncSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/FreeSyncSuite.scala
similarity index 89%
rename from laws/shared/src/test/scala/cats/effect/laws/FreeSyncSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/FreeSyncSuite.scala
index db0ab59f59..b81758550b 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/FreeSyncSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/FreeSyncSuite.scala
@@ -23,13 +23,11 @@ import cats.effect.kernel.testkit.freeEval.{syncForFreeT, FreeEitherSync}
 import cats.free.FreeT
 import cats.laws.discipline.arbitrary._
 
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
+import munit.DisciplineSuite
 
-class FreeSyncSpec
-    extends Specification
-    with Discipline
-    with BaseSpec
+class FreeSyncSuite
+    extends DisciplineSuite
+    with BaseSuite
     with LowPriorityImplicits {
   import FreeSyncGenerators._
   import SyncTypeGenerators._
diff --git a/laws/shared/src/test/scala/cats/effect/laws/GenTemporalSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/GenTemporalSuite.scala
similarity index 72%
rename from laws/shared/src/test/scala/cats/effect/laws/GenTemporalSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/GenTemporalSuite.scala
index 5403c86f98..d26856f24a 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/GenTemporalSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/GenTemporalSuite.scala
@@ -23,12 +23,12 @@ import cats.effect.kernel.testkit.TimeT
 import cats.effect.kernel.testkit.pure._
 import cats.syntax.all._
 
-import org.specs2.mutable.Specification
-
 import scala.concurrent.duration._
+
+import munit.FunSuite
 // import scala.concurrent.TimeoutException
 
-class GenTemporalSpec extends Specification { outer =>
+class GenTemporalSuite extends FunSuite { outer =>
 
   type F[A] = PureConc[Throwable, A]
 
@@ -37,28 +37,20 @@ class GenTemporalSpec extends Specification { outer =>
 
   val loop: TimeT[F, Unit] = F.sleep(5.millis).foreverM
 
-  "temporal" should {
-    "timeout" should {
-      "return identity when infinite duration" in {
-        val fa = F.pure(true)
-        F.timeout(fa, Duration.Inf) mustEqual fa
-      }
-    }
+  test("timeout should return identity when infinite duration") {
+    val fa = F.pure(true)
+    assertEquals(F.timeout(fa, Duration.Inf), fa)
+  }
 
-    "timeoutTo" should {
-      "return identity when infinite duration" in {
-        val fa: TimeT[F, Boolean] = F.pure(true)
-        val fallback: TimeT[F, Boolean] = F.raiseError(new RuntimeException)
-        F.timeoutTo(fa, Duration.Inf, fallback) mustEqual fa
-      }
-    }
+  test("timeoutTo should return identity when infinite duration") {
+    val fa: TimeT[F, Boolean] = F.pure(true)
+    val fallback: TimeT[F, Boolean] = F.raiseError(new RuntimeException)
+    assertEquals(F.timeoutTo(fa, Duration.Inf, fallback), fa)
+  }
 
-    "timeoutAndForget" should {
-      "return identity when infinite duration" in {
-        val fa: TimeT[F, Boolean] = F.pure(true)
-        F.timeoutAndForget(fa, Duration.Inf) mustEqual fa
-      }
-    }
+  test("timeoutAndForget should return identity when infinite duration") {
+    val fa: TimeT[F, Boolean] = F.pure(true)
+    assertEquals(F.timeoutAndForget(fa, Duration.Inf), fa)
   }
 
   // TODO enable these tests once Temporal for TimeT is fixed
diff --git a/laws/shared/src/test/scala/cats/effect/laws/IorTFreeSyncSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/IorTFreeSyncSuite.scala
similarity index 88%
rename from laws/shared/src/test/scala/cats/effect/laws/IorTFreeSyncSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/IorTFreeSyncSuite.scala
index ba237839f4..8fa7516e46 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/IorTFreeSyncSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/IorTFreeSyncSuite.scala
@@ -24,13 +24,11 @@ import cats.effect.kernel.testkit.freeEval.{syncForFreeT, FreeEitherSync}
 import cats.free.FreeT
 import cats.laws.discipline.arbitrary._
 
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
+import munit.DisciplineSuite
 
-class IorTFreeSyncSpec
-    extends Specification
-    with Discipline
-    with BaseSpec
+class IorTFreeSyncSuite
+    extends DisciplineSuite
+    with BaseSuite
     with LowPriorityImplicits {
   import FreeSyncGenerators._
   import SyncTypeGenerators._
diff --git a/laws/shared/src/test/scala/cats/effect/laws/IorTPureConcSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/IorTPureConcSuite.scala
similarity index 89%
rename from laws/shared/src/test/scala/cats/effect/laws/IorTPureConcSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/IorTPureConcSuite.scala
index bd549763c2..23763596e0 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/IorTPureConcSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/IorTPureConcSuite.scala
@@ -24,12 +24,12 @@ import cats.effect.kernel.testkit.pure._
 import cats.laws.discipline.arbitrary._
 
 import org.scalacheck.Prop
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
 
 import scala.concurrent.duration._
 
-class IorTPureConcSpec extends Specification with Discipline with BaseSpec {
+import munit.DisciplineSuite
+
+class IorTPureConcSuite extends DisciplineSuite with BaseSuite {
   import PureConcGenerators._
   import OutcomeGenerators._
 
diff --git a/laws/shared/src/test/scala/cats/effect/laws/KleisliFreeSyncSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/KleisliFreeSyncSuite.scala
similarity index 88%
rename from laws/shared/src/test/scala/cats/effect/laws/KleisliFreeSyncSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/KleisliFreeSyncSuite.scala
index df2ac2631a..990f723d68 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/KleisliFreeSyncSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/KleisliFreeSyncSuite.scala
@@ -26,13 +26,11 @@ import cats.laws.discipline.MiniInt
 import cats.laws.discipline.arbitrary._
 import cats.laws.discipline.eq._
 
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
+import munit.DisciplineSuite
 
-class KleisliFreeSyncSpec
-    extends Specification
-    with Discipline
-    with BaseSpec
+class KleisliFreeSyncSuite
+    extends DisciplineSuite
+    with BaseSuite
     with LowPriorityImplicits {
   import FreeSyncGenerators._
   import SyncTypeGenerators._
diff --git a/laws/shared/src/test/scala/cats/effect/laws/KleisliPureConcSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/KleisliPureConcSuite.scala
similarity index 93%
rename from laws/shared/src/test/scala/cats/effect/laws/KleisliPureConcSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/KleisliPureConcSuite.scala
index 843a58c8d2..bd05c5eab5 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/KleisliPureConcSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/KleisliPureConcSuite.scala
@@ -26,16 +26,14 @@ import cats.effect.kernel.testkit.pure._
 import cats.laws.discipline.{arbitrary, MiniInt}
 
 import org.scalacheck.{Arbitrary, Cogen, Prop}
-import org.specs2.mutable._
-import org.specs2.scalacheck.Parameters
-import org.typelevel.discipline.specs2.mutable.Discipline
 
 import scala.concurrent.duration._
 
-class KleisliPureConcSpec
-    extends Specification
-    with Discipline
-    with BaseSpec
+import munit.DisciplineSuite
+
+class KleisliPureConcSuite
+    extends DisciplineSuite
+    with BaseSuite
     with LowPriorityKleisliInstances {
   import PureConcGenerators._
   import arbitrary.{catsLawsArbitraryForKleisli => _, _}
@@ -78,12 +76,16 @@ class KleisliPureConcSpec
       : Cogen[Outcome[Kleisli[TimeT[PureConc[Int, *], *], MiniInt, *], Int, A]] =
     OutcomeGenerators.cogenOutcome[Kleisli[TimeT[PureConc[Int, *], *], MiniInt, *], Int, A]
 
+  override def scalaCheckTestParameters =
+    super.scalaCheckTestParameters
+    // we need to bound this a little tighter because these tests take FOREVER
+      .withMinSuccessfulTests(25)
+
   checkAll(
     "Kleisli[PureConc]",
     GenTemporalTests[Kleisli[TimeT[PureConc[Int, *], *], MiniInt, *], Int]
       .temporal[Int, Int, Int](10.millis)
-    // we need to bound this a little tighter because these tests take FOREVER
-  )(Parameters(minTestsOk = 25))
+  )
 }
 
 //Push the priority of Kleisli instances down so we can explicitly summon more
diff --git a/laws/shared/src/test/scala/cats/effect/laws/OptionTFreeSyncSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/OptionTFreeSyncSuite.scala
similarity index 87%
rename from laws/shared/src/test/scala/cats/effect/laws/OptionTFreeSyncSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/OptionTFreeSyncSuite.scala
index 4f3fd18438..a848b21916 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/OptionTFreeSyncSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/OptionTFreeSyncSuite.scala
@@ -24,10 +24,9 @@ import cats.effect.kernel.testkit.freeEval.{syncForFreeT, FreeEitherSync}
 import cats.free.FreeT
 import cats.laws.discipline.arbitrary._
 
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
+import munit.DisciplineSuite
 
-class OptionTFreeSyncSpec extends Specification with Discipline with BaseSpec with FreeSyncEq {
+class OptionTFreeSyncSuite extends DisciplineSuite with BaseSuite with FreeSyncEq {
 
   import FreeSyncGenerators._
   import SyncTypeGenerators._
diff --git a/laws/shared/src/test/scala/cats/effect/laws/OptionTPureConcSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/OptionTPureConcSuite.scala
similarity index 79%
rename from laws/shared/src/test/scala/cats/effect/laws/OptionTPureConcSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/OptionTPureConcSuite.scala
index 269bdced8d..5c76a996d9 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/OptionTPureConcSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/OptionTPureConcSuite.scala
@@ -28,12 +28,12 @@ import cats.laws.discipline.arbitrary._
 import cats.syntax.all._
 
 import org.scalacheck.Prop
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
 
 import scala.concurrent.duration._
 
-class OptionTPureConcSpec extends Specification with Discipline with BaseSpec {
+import munit.DisciplineSuite
+
+class OptionTPureConcSuite extends DisciplineSuite with BaseSuite {
   import PureConcGenerators._
   import OutcomeGenerators._
 
@@ -47,26 +47,21 @@ class OptionTPureConcSpec extends Specification with Discipline with BaseSpec {
           bO => bO.flatten.fold(false)(_ => true)
         ))
 
-  "optiont bracket" should {
-    "forward completed zeros on to the handler" in {
+    test("optiont bracket forward completed zeros on to the handler") {
       var observed = false
 
       val test = OptionT.none[PureConc[Int, *], Unit] guaranteeCase {
         case Outcome.Succeeded(fa) =>
           observed = true
 
-          OptionT(fa.value.map(_ must beNone).as(None))
+          OptionT(fa.value.map(assertEquals(_, None)).as(None))
 
         case _ => Applicative[OptionT[PureConc[Int, *], *]].unit
       }
 
-      pure.run(test.value) must beLike {
-        case Outcome.Succeeded(Some(None)) => ok
-        case _ => ko
-      }
+      assert(pure.run(test.value) === Outcome.Succeeded(Some(Option.empty[Unit])))
 
-      observed must beTrue
-    }
+      assert(observed)
   }
 
   checkAll(
diff --git a/laws/shared/src/test/scala/cats/effect/laws/PureConcSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/PureConcSuite.scala
similarity index 63%
rename from laws/shared/src/test/scala/cats/effect/laws/PureConcSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/PureConcSuite.scala
index 6e4de84133..e4495a2e84 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/PureConcSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/PureConcSuite.scala
@@ -23,19 +23,19 @@ import cats.effect.kernel.testkit.pure._
 import cats.laws.discipline.arbitrary._
 
 import org.scalacheck.Prop
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
 
 import scala.concurrent.duration._
 
-class PureConcSpec extends Specification with Discipline with BaseSpec {
+import munit.DisciplineSuite
+
+class PureConcSuite extends DisciplineSuite with BaseSuite {
   import PureConcGenerators._
   import OutcomeGenerators._
 
   implicit def exec(fb: TimeT[PureConc[Int, *], Boolean]): Prop =
     Prop(pure.run(TimeT.run(fb)).fold(false, _ => false, _.getOrElse(false)))
 
-  "parallel utilities" should {
+  {
     import cats.effect.kernel.{GenConcurrent, Outcome}
     import cats.effect.kernel.implicits._
     import cats.syntax.all._
@@ -43,35 +43,37 @@ class PureConcSpec extends Specification with Discipline with BaseSpec {
     type F[A] = PureConc[Int, A]
     val F = GenConcurrent[F]
 
-    "short-circuit on error" in {
-      pure.run((F.never[Unit], F.raiseError[Unit](42)).parTupled) mustEqual Outcome.Errored(42)
-      pure.run((F.raiseError[Unit](42), F.never[Unit]).parTupled) mustEqual Outcome.Errored(42)
+    test("short-circuit on error") {
+      assert(
+        pure.run((F.never[Unit], F.raiseError[Unit](42)).parTupled) === Outcome.Errored(42))
+      assertEquals(
+        pure.run((F.raiseError[Unit](42), F.never[Unit]).parTupled),
+        Outcome.Errored[Option, Int, (Unit, Unit)](42))
     }
 
-    "short-circuit on canceled" in {
-      pure.run((F.never[Unit], F.canceled).parTupled.start.flatMap(_.join)) mustEqual Outcome
-        .Succeeded(Some(Outcome.canceled[F, Nothing, Unit]))
-      pure.run((F.canceled, F.never[Unit]).parTupled.start.flatMap(_.join)) mustEqual Outcome
-        .Succeeded(Some(Outcome.canceled[F, Nothing, Unit]))
+    test("short-circuit on canceled") {
+      assert(
+        pure.run((F.never[Unit], F.canceled).parTupled.start.flatMap(_.join)) === Outcome
+          .Succeeded(Some(Outcome.canceled[F, Int, (Unit, Unit)])))
+      assert(
+        pure.run((F.canceled, F.never[Unit]).parTupled.start.flatMap(_.join)) === Outcome
+          .Succeeded(Some(Outcome.canceled[F, Int, (Unit, Unit)])))
     }
 
-    "not run forever on chained product" in {
+    test("not run forever on chained product") {
       import cats.effect.kernel.Par.ParallelF
 
       val fa: F[String] = F.pure("a")
       val fb: F[String] = F.pure("b")
       val fc: F[Unit] = F.raiseError[Unit](42)
-      pure.run(
-        ParallelF.value(
-          ParallelF(fa).product(ParallelF(fb)).product(ParallelF(fc)))) mustEqual Outcome
-        .Errored(42)
+      assert(pure.run(ParallelF.value(
+        ParallelF(fa).product(ParallelF(fb)).product(ParallelF(fc)))) === Outcome.Errored(42))
     }
 
-    "ignore unmasking in finalizers" in {
+    test("ignore unmasking in finalizers") {
       val fa = F.uncancelable { poll => F.onCancel(poll(F.unit), poll(F.unit)) }
 
       pure.run(fa.start.flatMap(_.cancel))
-      ok
     }
   }
 
diff --git a/laws/shared/src/test/scala/cats/effect/laws/ReaderWriterStateTFreeSyncSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/ReaderWriterStateTFreeSyncSuite.scala
similarity index 81%
rename from laws/shared/src/test/scala/cats/effect/laws/ReaderWriterStateTFreeSyncSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/ReaderWriterStateTFreeSyncSuite.scala
index 4df3ba5724..721ead60e3 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/ReaderWriterStateTFreeSyncSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/ReaderWriterStateTFreeSyncSuite.scala
@@ -25,23 +25,20 @@ import cats.free.FreeT
 import cats.laws.discipline.MiniInt
 import cats.laws.discipline.arbitrary._
 
-import org.specs2.mutable._
-import org.specs2.scalacheck._
-import org.typelevel.discipline.specs2.mutable.Discipline
+import munit.DisciplineSuite
 
-class ReaderWriterStateTFreeSyncSpec
-    extends Specification
-    with Discipline
-    with BaseSpec
+class ReaderWriterStateTFreeSyncSuite
+    extends DisciplineSuite
+    with BaseSuite
     with LowPriorityImplicits {
   import FreeSyncGenerators._
   import SyncTypeGenerators._
 
-  implicit val params: Parameters =
+  override def scalaCheckTestParameters =
     if (cats.platform.Platform.isNative)
-      Parameters(minTestsOk = 5)
+      super.scalaCheckTestParameters.withMinSuccessfulTests(5)
     else
-      Parameters(minTestsOk = 100)
+      super.scalaCheckTestParameters
 
   implicit val scala_2_12_is_buggy
       : Eq[FreeT[Eval, Either[Throwable, *], Either[Int, Either[Throwable, Int]]]] =
diff --git a/laws/shared/src/test/scala/cats/effect/laws/ReaderWriterStateTPureConcSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/ReaderWriterStateTPureConcSuite.scala
similarity index 85%
rename from laws/shared/src/test/scala/cats/effect/laws/ReaderWriterStateTPureConcSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/ReaderWriterStateTPureConcSuite.scala
index 4c16bcd7d7..a303cac487 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/ReaderWriterStateTPureConcSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/ReaderWriterStateTPureConcSuite.scala
@@ -25,21 +25,22 @@ import cats.laws.discipline.MiniInt
 import cats.laws.discipline.arbitrary._
 import cats.laws.discipline.eq._
 
-import org.specs2.mutable._
-import org.specs2.scalacheck.Parameters
-import org.typelevel.discipline.specs2.mutable.Discipline
+import munit.DisciplineSuite
 
-class ReaderWriterStateTPureConcSpec extends Specification with Discipline with BaseSpec {
+class ReaderWriterStateTPureConcSuite extends DisciplineSuite with BaseSuite {
   import PureConcGenerators._
 
   implicit def rwstEq[F[_]: Monad, E, L, S, A](
       implicit ev: Eq[(E, S) => F[(L, S, A)]]): Eq[ReaderWriterStateT[F, E, L, S, A]] =
     Eq.by[ReaderWriterStateT[F, E, L, S, A], (E, S) => F[(L, S, A)]](_.run)
 
+  override def scalaCheckTestParameters =
+    // we need to bound this a little tighter because these tests take FOREVER, especially on scalajs
+    super.scalaCheckTestParameters.withMinSuccessfulTests(1)
+
   checkAll(
     "ReaderWriterStateT[PureConc]",
     MonadCancelTests[ReaderWriterStateT[PureConc[Int, *], MiniInt, Int, MiniInt, *], Int]
       .monadCancel[Int, Int, Int]
-    // we need to bound this a little tighter because these tests take FOREVER, especially on scalajs
-  )(Parameters(minTestsOk = 1))
+  )
 }
diff --git a/laws/shared/src/test/scala/cats/effect/laws/ResourcePureConcSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/ResourcePureConcSuite.scala
similarity index 89%
rename from laws/shared/src/test/scala/cats/effect/laws/ResourcePureConcSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/ResourcePureConcSuite.scala
index 406d781f51..a0735d65ed 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/ResourcePureConcSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/ResourcePureConcSuite.scala
@@ -23,13 +23,12 @@ import cats.laws.discipline.arbitrary._
 import cats.syntax.all._
 
 import org.scalacheck.{Cogen, Prop}
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
 
-class ResourcePureConcSpec
-    extends Specification
-    with Discipline
-    with BaseSpec
+import munit.DisciplineSuite
+
+class ResourcePureConcSuite
+    extends DisciplineSuite
+    with BaseSuite
     with TestInstances {
   import PureConcGenerators._
   import OutcomeGenerators._
diff --git a/laws/shared/src/test/scala/cats/effect/laws/StateTFreeSyncSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/StateTFreeSyncSuite.scala
similarity index 88%
rename from laws/shared/src/test/scala/cats/effect/laws/StateTFreeSyncSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/StateTFreeSyncSuite.scala
index ad44aa909c..209497cfa5 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/StateTFreeSyncSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/StateTFreeSyncSuite.scala
@@ -25,13 +25,11 @@ import cats.free.FreeT
 import cats.laws.discipline.MiniInt
 import cats.laws.discipline.arbitrary._
 
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
+import munit.DisciplineSuite
 
-class StateTFreeSyncSpec
-    extends Specification
-    with Discipline
-    with BaseSpec
+class StateTFreeSyncSuite
+    extends DisciplineSuite
+    with BaseSuite
     with LowPriorityImplicits {
   import FreeSyncGenerators._
   import SyncTypeGenerators._
diff --git a/laws/shared/src/test/scala/cats/effect/laws/StateTPureConcSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/StateTPureConcSuite.scala
similarity index 78%
rename from laws/shared/src/test/scala/cats/effect/laws/StateTPureConcSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/StateTPureConcSuite.scala
index c8e6b1d73e..828c20ab4d 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/StateTPureConcSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/StateTPureConcSuite.scala
@@ -25,20 +25,22 @@ import cats.laws.discipline.MiniInt
 import cats.laws.discipline.arbitrary._
 import cats.laws.discipline.eq._
 
-import org.specs2.mutable._
-import org.specs2.scalacheck.Parameters
-import org.typelevel.discipline.specs2.mutable.Discipline
+import munit.DisciplineSuite
 
-class StateTPureConcSpec extends Specification with Discipline with BaseSpec {
+class StateTPureConcSuite extends DisciplineSuite with BaseSuite {
   import PureConcGenerators._
 
   implicit def stateTEq[F[_]: FlatMap, S, A](
       implicit ev: Eq[S => F[(S, A)]]): Eq[StateT[F, S, A]] =
     Eq.by[StateT[F, S, A], S => F[(S, A)]](_.run)
 
+  override def scalaCheckTestParameters =
+    super.scalaCheckTestParameters.withMinSuccessfulTests(25)
+
+  // override def scalaCheckInitialSeed = "Ky43MND8m5h-10MZTckMFFAW6ea2pXWkFDE2A7ddtML="
+
   checkAll(
     "StateT[PureConc]",
     MonadCancelTests[StateT[PureConc[Int, *], MiniInt, *], Int].monadCancel[Int, Int, Int]
-  )(Parameters(minTestsOk =
-    25 /*, seed = Some(Seed.fromBase64("Ky43MND8m5h-10MZTckMFFAW6ea2pXWkFDE2A7ddtML=").get*/ ))
+  )
 }
diff --git a/laws/shared/src/test/scala/cats/effect/laws/WriterTFreeSyncSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/WriterTFreeSyncSuite.scala
similarity index 88%
rename from laws/shared/src/test/scala/cats/effect/laws/WriterTFreeSyncSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/WriterTFreeSyncSuite.scala
index 59c5fea21f..35f60abee1 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/WriterTFreeSyncSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/WriterTFreeSyncSuite.scala
@@ -24,13 +24,11 @@ import cats.effect.kernel.testkit.freeEval.{syncForFreeT, FreeEitherSync}
 import cats.free.FreeT
 import cats.laws.discipline.arbitrary._
 
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
+import munit.DisciplineSuite
 
-class WriterTFreeSyncSpec
-    extends Specification
-    with Discipline
-    with BaseSpec
+class WriterTFreeSyncSuite
+    extends DisciplineSuite
+    with BaseSuite
     with LowPriorityImplicits {
   import FreeSyncGenerators._
   import SyncTypeGenerators._
diff --git a/laws/shared/src/test/scala/cats/effect/laws/WriterTPureConcSpec.scala b/laws/shared/src/test/scala/cats/effect/laws/WriterTPureConcSuite.scala
similarity index 89%
rename from laws/shared/src/test/scala/cats/effect/laws/WriterTPureConcSpec.scala
rename to laws/shared/src/test/scala/cats/effect/laws/WriterTPureConcSuite.scala
index 3663c442ac..3bb40f9c39 100644
--- a/laws/shared/src/test/scala/cats/effect/laws/WriterTPureConcSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/laws/WriterTPureConcSuite.scala
@@ -24,12 +24,12 @@ import cats.effect.kernel.testkit.pure._
 import cats.laws.discipline.arbitrary._
 
 import org.scalacheck.Prop
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
 
 import scala.concurrent.duration._
 
-class WriterTPureConcSpec extends Specification with Discipline with BaseSpec {
+import munit.DisciplineSuite
+
+class WriterTPureConcSuite extends DisciplineSuite with BaseSuite {
   import PureConcGenerators._
   import OutcomeGenerators._
 
diff --git a/laws/shared/src/test/scala/cats/effect/testkit/TimeTSpec.scala b/laws/shared/src/test/scala/cats/effect/testkit/TimeTSuite.scala
similarity index 92%
rename from laws/shared/src/test/scala/cats/effect/testkit/TimeTSpec.scala
rename to laws/shared/src/test/scala/cats/effect/testkit/TimeTSuite.scala
index 218eccc97d..3e8f7ae87b 100644
--- a/laws/shared/src/test/scala/cats/effect/testkit/TimeTSpec.scala
+++ b/laws/shared/src/test/scala/cats/effect/testkit/TimeTSuite.scala
@@ -23,20 +23,20 @@ import cats.effect.laws.GenTemporalTests
 import cats.laws.discipline.arbitrary._
 
 import org.scalacheck.{Arbitrary, Cogen, Gen, Prop}
-import org.specs2.mutable._
-import org.typelevel.discipline.specs2.mutable.Discipline
 
 import scala.concurrent.duration._
 
 import java.util.concurrent.TimeUnit
 
+import munit.DisciplineSuite
+
 private[testkit] trait LowPriorityInstances {
 
   implicit def eqTimeT[F[_], A](implicit FA: Eq[F[A]]): Eq[TimeT[F, A]] =
     Eq.by(TimeT.run(_))
 }
 
-class TimeTSpec extends Specification with Discipline with LowPriorityInstances {
+class TimeTSuite extends DisciplineSuite with LowPriorityInstances {
 
   import PureConcGenerators._
   import OutcomeGenerators._