diff --git a/.travis.yml b/.travis.yml
index 8e15b8c..be39a9b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,8 @@
 language: scala
 scala:
-  - 2.10.7
   - 2.11.12
   - 2.12.6
-  - 2.13.0-M3
+  - 2.13.0-M4
 jdk:
   - oraclejdk8
 script:
diff --git a/build.sbt b/build.sbt
index 6ad68f3..f17927d 100644
--- a/build.sbt
+++ b/build.sbt
@@ -10,7 +10,7 @@ import com.typesafe.sbt.pgp.PgpKeys._
 name := "discipline root project"
 
 lazy val commonSettings = Seq(
-  crossScalaVersions := Seq("2.10.7", "2.11.12", "2.12.6", "2.13.0-M3"),
+  crossScalaVersions := Seq("2.11.12", "2.12.6", "2.13.0-M4"),
   organization := "org.typelevel",
   name := "discipline",
   scalaVersion := "2.12.6",
@@ -21,17 +21,10 @@ lazy val commonSettings = Seq(
     "-language:implicitConversions"
   ),
   libraryDependencies ++= Seq(
-    "org.scalacheck" %%% "scalacheck" % "1.13.5"
+    "org.scalacheck" %%% "scalacheck" % "1.14.0",
+    "org.scalatest" %%% "scalatest" % "3.0.6-SNAP1" % "optional",
+    "org.specs2" %%% "specs2-scalacheck" % "4.3.0" % "optional"
   ),
-  libraryDependencies += {
-    CrossVersion.partialVersion(scalaVersion.value) match {
-      case Some((2, 13)) =>
-        "org.scalatest" %%% "scalatest" % "3.0.5-M1" % "optional"
-      case _ =>
-        "org.scalatest" %%% "scalatest" % "3.0.5" % "optional"
-    }
-  },
-  resolvers += "scalaz-bintray" at "http://dl.bintray.com/scalaz/releases",
   scalacOptions in Test ++= Seq("-Yrangepos"),
 
   releaseProcess := Seq[ReleaseStep](
@@ -90,8 +83,6 @@ lazy val commonSettings = Seq(
   )
 )
 
-val specs2Version = SettingKey[String]("specs2Version")
-
 lazy val root = project.in(file("."))
   .settings(commonSettings: _*)
   .settings(noPublishSettings: _*)
@@ -99,43 +90,7 @@ lazy val root = project.in(file("."))
 
 lazy val discipline = crossProject.in(file("."))
   .settings(commonSettings: _*)
-  .jvmSettings(
-     specs2Version := {
-      CrossVersion.partialVersion(scalaVersion.value) match {
-        case Some((2, n)) if n == 10 =>
-          "3.9.1"
-        case _ =>
-          "4.0.3"
-      }
-    },
-    libraryDependencies ++= Seq(
-      "org.specs2" %% "specs2-core"       % specs2Version.value % "optional",
-      "org.specs2" %% "specs2-scalacheck" % specs2Version.value % "optional"
-    )
-  )
-  .jsSettings(
-    scalaJSStage in Test := FastOptStage,
-    specs2Version := "4.0.3",
-    libraryDependencies ++= {
-      CrossVersion.partialVersion(scalaVersion.value) match {
-        case Some((2, n)) if n == 10 =>
-          Seq()
-        case _ =>
-          Seq(
-            "org.specs2" %%% "specs2-core"       % specs2Version.value % "optional",
-            "org.specs2" %%% "specs2-scalacheck" % specs2Version.value % "optional"
-          )
-      }
-    },
-    excludeFilter in unmanagedSources := {
-      CrossVersion.partialVersion(scalaVersion.value) match {
-        case Some((2, n)) if n == 10 =>
-          HiddenFileFilter || "*specs2*" || "*LawSpec.scala"
-        case _ =>
-          ""
-      }
-    }
-  )
+  .jsSettings(scalaJSStage in Test := FastOptStage)
 
 lazy val disciplineJVM = discipline.jvm
 lazy val disciplineJS = discipline.js
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 2a8fdee..124578c 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -1,3 +1,3 @@
 addSbtPlugin("com.jsuereth"  % "sbt-pgp"     % "1.1.0")
 addSbtPlugin("com.github.gseitz" % "sbt-release" % "1.0.7")
-addSbtPlugin("org.scala-js"      % "sbt-scalajs" % "0.6.22")
+addSbtPlugin("org.scala-js"      % "sbt-scalajs" % "0.6.23")
diff --git a/shared/src/main/scala/specs2/Discipline.scala b/shared/src/main/scala/specs2/Discipline.scala
index e34ea5a..fd4ac52 100644
--- a/shared/src/main/scala/specs2/Discipline.scala
+++ b/shared/src/main/scala/specs2/Discipline.scala
@@ -12,7 +12,7 @@ trait Discipline extends ScalaCheck { self: SpecificationLike =>
 
   def checkAll(name: String, ruleSet: Laws#RuleSet)(implicit p: Parameters) = {
     s"""${ruleSet.name} laws must hold for ${name}""" ^ br ^
-    Fragments.foreach(ruleSet.all.properties) { case (id, prop) =>
+    Fragments.foreach(ruleSet.all.properties.toList) { case (id, prop) =>
        id ! check(prop, p, defaultFreqMapPretty) ^ br
     }
   }
diff --git a/shared/src/main/scala/specs2/mutable/Discipline.scala b/shared/src/main/scala/specs2/mutable/Discipline.scala
index f047fd1..96c309f 100644
--- a/shared/src/main/scala/specs2/mutable/Discipline.scala
+++ b/shared/src/main/scala/specs2/mutable/Discipline.scala
@@ -11,9 +11,9 @@ import org.specs2.specification.core.Fragments
 trait Discipline extends ScalaCheck { self: SpecificationLike =>
 
   def checkAll(name: String, ruleSet: Laws#RuleSet)(implicit p: Parameters) = {
-  	s"""${ruleSet.name} laws must hold for ${name}""".txt
-  	br
-    Fragments.foreach(ruleSet.all.properties) { case (id, prop) =>
+    s"""${ruleSet.name} laws must hold for ${name}""".txt
+    br
+    Fragments.foreach(ruleSet.all.properties.toList) { case (id, prop) =>
       id in check(prop, p, defaultFreqMapPretty)
     }
   }