diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2633023..1b77fc7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [ '8', '11']
+        java: [ '11', '17']
     name: Run Tests (Java ${{ matrix.java }})
     steps:
     - name: Checkout
diff --git a/atom-manager-play-lib/build.sbt b/atom-manager-play-lib/build.sbt
index acd7492..7913c55 100644
--- a/atom-manager-play-lib/build.sbt
+++ b/atom-manager-play-lib/build.sbt
@@ -5,7 +5,7 @@ name := "atom-manager-play"
 libraryDependencies ++= Seq(
   "com.typesafe.play"      %% "play"                  % playVersion,
   "com.gu"                 %% "content-atom-model"    % contentAtomVersion,
-  "org.scalatestplus.play" %% "scalatestplus-play"    % "5.1.0" % Test,
+  "org.scalatestplus.play" %% "scalatestplus-play"    % "6.0.1" % Test,
   "com.amazonaws"          %  "aws-java-sdk-dynamodb" % awsVersion,
   "org.mockito"            %  "mockito-core"          % mockitoVersion % Test,
   "com.typesafe.play"      %% "play-test"             % playVersion % Test,
diff --git a/build.sbt b/build.sbt
index 756580f..642a708 100644
--- a/build.sbt
+++ b/build.sbt
@@ -6,10 +6,9 @@ name := "atom-maker-lib"
 
 lazy val artifactProductionSettings = Seq(
   organization := "com.gu",
-  scalaVersion := "2.12.18",
-  crossScalaVersions := Seq(scalaVersion.value, "2.13.12"),
+  scalaVersion := "2.13.12",
   licenses := Seq(License.Apache2),
-  scalacOptions := Seq("-deprecation", "-feature", "-release:8")
+  scalacOptions := Seq("-deprecation", "-feature", "-release:11")
 )
 
 lazy val atomPublisher = (project in file("./atom-publisher-lib"))
@@ -32,7 +31,6 @@ lazy val atomLibraries = (project in file("."))
   .aggregate(atomPublisher, atomManagerPlay).settings(
     publish / skip := true,
     releaseVersion := ReleaseVersion.fromAggregatedAssessedCompatibilityWithLatestRelease().value,
-    releaseCrossBuild := true, // true if you cross-build the project for multiple Scala versions
     releaseProcess := Seq[ReleaseStep](
       checkSnapshotDependencies,
       inquireVersions,
diff --git a/project/BuildVars.scala b/project/BuildVars.scala
index d5490e8..b760cff 100644
--- a/project/BuildVars.scala
+++ b/project/BuildVars.scala
@@ -4,6 +4,6 @@ object BuildVars {
   lazy val awsVersion         = "1.11.8"
   lazy val contentAtomVersion = "4.0.0"
   lazy val scroogeVersion     = "22.1.0"
-  lazy val playVersion        = "2.8.8"
-  lazy val mockitoVersion     = "4.8.0"
+  lazy val playVersion        = "2.9.1"
+  lazy val mockitoVersion     = "4.11.0"
 }
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 39b41a1..698656a 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -1,4 +1,4 @@
-addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.8.8")
+addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.9.1")
 
 addSbtPlugin("com.github.sbt" % "sbt-release" % "1.1.0")
 addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "3.10.0")