diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index aff3535b..ecf9316f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,8 +13,8 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [ '13', '18' ]
-        scala: [ '2.13.8' ]
+        java: [ '17' ]
+        scala: [ '2.13.11' ]
     steps:
     - uses: actions/checkout@v2
     - name: Set up JDK
@@ -25,4 +25,4 @@ jobs:
     - name: print Java version
       run: java -version
     - name: Build
-      run: sbt ++${{ matrix.scala }} clean coverage test coverageReport
+      run: sbt ++${{ matrix.scala }} clean test
diff --git a/.travis.yml b/.travis.yml
index 77366fb5..847a9c2c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,7 +6,7 @@ cache:
     - $HOME/.ivy2/cache
     - $HOME/.sbt/boot/
 script:
-  - sbt clean coverage test coverageReport
+  - sbt clean test
   # Tricks to avoid unnecessary cache updates
   - find $HOME/.sbt -name "*.lock" | xargs rm -f
   - find $HOME/.ivy2 -name "ivydata-*.properties" | xargs rm -f
diff --git a/DEVELOPER.md b/DEVELOPER.md
index 9741960f..318d69dc 100644
--- a/DEVELOPER.md
+++ b/DEVELOPER.md
@@ -3,7 +3,3 @@ Running
     sbt
     > project generator
     > run
-
-Code coverage
-=============
-    sbt clean coverage test coverageReport
diff --git a/Dockerfile b/Dockerfile
index 085f3b73..8e1104bb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,9 @@
-FROM flowdocker/play_builder:latest-java13 as builder
+FROM flowdocker/play_builder:latest-java17 as builder
 ADD . /opt/play
 WORKDIR /opt/play
 RUN sbt 'project generator' clean stage
 
-FROM flowdocker/play:latest-java13
+FROM flowdocker/play:latest-java17
 COPY --from=builder /opt/play /opt/play
 WORKDIR /opt/play/generator/target/universal/stage
 ENTRYPOINT ["java", "-jar", "/root/environment-provider.jar", "--service", "play", "apibuilder-generator", "bin/apibuilder-generator-generator"]
diff --git a/build.sbt b/build.sbt
index 48185a30..45a809be 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,10 +1,10 @@
-import scoverage.ScoverageKeys
-
 name := "apibuilder-generator"
 
 organization := "io.apibuilder.generator"
 
-ThisBuild / scalaVersion := "2.13.8"
+ThisBuild / scalaVersion := "2.13.11"
+
+ThisBuild / javacOptions ++= Seq("-source", "17", "-target", "17")
 
 lazy val allScalacOptions = Seq(
   "-deprecation",
@@ -36,6 +36,10 @@ lazy val generated = project
       "org.scalacheck" %% "scalacheck" % "1.15.4" % Test
     ),
     scalacOptions ++= allScalacOptions,
+    Test / javaOptions ++= Seq(
+      "--add-exports=java.base/sun.security.x509=ALL-UNNAMED",
+      "--add-opens=java.base/sun.security.ssl=ALL-UNNAMED"
+    )
   )
 
 // TODO: lib will eventually be published as a jar if it turns out
@@ -48,8 +52,8 @@ lazy val lib = project
 
 lazy val generator = project
   .in(file("generator"))
-  .dependsOn(csharpGenerator, scalaGenerator, rubyGenerator, javaGenerator, goGenerator, androidGenerator, kotlinGenerator, graphQLGenerator, javaAwsLambdaPojos, postmanGenerator, csvGenerator)
-  .aggregate(csharpGenerator, scalaGenerator, rubyGenerator, javaGenerator, goGenerator, androidGenerator, kotlinGenerator, graphQLGenerator, javaAwsLambdaPojos, postmanGenerator, csvGenerator)
+  .dependsOn(elmGenerator, csharpGenerator, scalaGenerator, rubyGenerator, javaGenerator, goGenerator, androidGenerator, kotlinGenerator, graphQLGenerator, javaAwsLambdaPojos, postmanGenerator, csvGenerator)
+  .aggregate(elmGenerator, csharpGenerator, scalaGenerator, rubyGenerator, javaGenerator, goGenerator, androidGenerator, kotlinGenerator, graphQLGenerator, javaAwsLambdaPojos, postmanGenerator, csvGenerator)
   .enablePlugins(PlayScala)
   .enablePlugins(JavaAgent)
   .settings(commonSettings: _*)
@@ -63,6 +67,10 @@ lazy val generator = project
       "org.scalatestplus.play" %% "scalatestplus-play" % "5.0.0" % "test"
     ),
     scalacOptions ++= allScalacOptions,
+    Test / javaOptions ++= Seq(
+      "--add-exports=java.base/sun.security.x509=ALL-UNNAMED",
+      "--add-opens=java.base/sun.security.ssl=ALL-UNNAMED"
+    )
   )
 
 lazy val javaAwsLambdaPojos = project
@@ -70,7 +78,6 @@ lazy val javaAwsLambdaPojos = project
   .dependsOn(lib, lib % "test->test")
   .settings(commonSettings: _*)
   .settings(
-    Seq(ScoverageKeys.coverageMinimumStmtTotal := 69.5),
     libraryDependencies ++= Seq(
       "com.amazonaws" % "aws-java-sdk-dynamodb" % "1.11.461",
       "me.geso" % "tinyvalidator" % "0.9.1",
@@ -84,9 +91,8 @@ lazy val scalaGenerator = project
   .dependsOn(lib, lib % "test->test")
   .settings(commonSettings: _*)
   .settings(
-    Seq(ScoverageKeys.coverageMinimumStmtTotal := 85.4),
     libraryDependencies ++= Seq(
-      "org.typelevel" %% "cats-core" % "2.1.1",
+      "org.typelevel" %% "cats-core" % "2.10.0",
       "org.scalameta" %% "scalafmt-core" % "2.3.2"
     )
   )
@@ -97,7 +103,17 @@ lazy val csharpGenerator = project
   .settings(commonSettings: _*)
   .settings(
     libraryDependencies ++= Seq(
-      "org.typelevel" %% "cats-core" % "2.1.1"
+      "org.typelevel" %% "cats-core" % "2.10.0"
+    )
+  )
+
+lazy val elmGenerator = project
+  .in(file("elm-generator"))
+  .dependsOn(lib, lib % "test->test")
+  .settings(commonSettings: _*)
+  .settings(
+    libraryDependencies ++= Seq(
+      "org.typelevel" %% "cats-core" % "2.10.0"
     )
   )
 
@@ -105,13 +121,11 @@ lazy val rubyGenerator = project
   .in(file("ruby-generator"))
   .dependsOn(lib, lib % "test->test")
   .settings(commonSettings: _*)
-  .settings(Seq(ScoverageKeys.coverageMinimumStmtTotal := 86.5))
 
 lazy val javaGenerator = project
   .in(file("java-generator"))
   .dependsOn(lib, lib % "test->test")
   .settings(commonSettings: _*)
-  .settings(Seq(ScoverageKeys.coverageMinimumStmtTotal := 66.98))
 
 lazy val goGenerator = project
   .in(file("go-generator"))
@@ -124,14 +138,12 @@ lazy val androidGenerator = project
   .settings(
     commonSettings: _*
   )
-  .settings(Seq(ScoverageKeys.coverageMinimumStmtTotal := 76.90))
 
 lazy val graphQLGenerator = project
   .in(file("graphql-generator"))
   .dependsOn(lib, lib % "test->test")
   .settings(commonSettings: _*)
   .settings(resolversSettings)
-  .settings(Seq(ScoverageKeys.coverageMinimumStmtTotal := 66.98))
   .settings(
     libraryDependencies ++= Seq(
       "io.apibuilder" %% "apibuilder-graphql" % "0.0.10",
@@ -166,7 +178,6 @@ lazy val kotlinGenerator = project
       "org.mockito" % "mockito-core" % mockitoVersion % "test"
     )
   )
-  .settings(Seq(ScoverageKeys.coverageMinimumStmtTotal := 94.5, ScoverageKeys.coverageFailOnMinimum := true))
 
 lazy val csvGenerator = project
   .in(file("csv-generator"))
@@ -178,7 +189,6 @@ lazy val csvGenerator = project
       "org.apache.commons" % "commons-csv" % "1.7"
     )
   )
-  .settings(Seq(ScoverageKeys.coverageMinimumStmtTotal := 75.67, ScoverageKeys.coverageFailOnMinimum := true))
 
 lazy val postmanGenerator = project
   .in(file("postman-generator"))
@@ -193,7 +203,6 @@ lazy val postmanGenerator = project
 lazy val commonSettings: Seq[Setting[_]] = Seq(
   name ~= ("apibuilder-generator-" + _),
   organization := "io.apibuilder",
-  ScoverageKeys.coverageFailOnMinimum := true,
   testOptions += Tests.Argument("-oF"),
   libraryDependencies ++= Seq(
     "org.atteo" % "evo-inflector" % "1.2.2",
@@ -209,6 +218,10 @@ lazy val commonSettings: Seq[Setting[_]] = Seq(
   ),
   libraryDependencies += guice,
   scalacOptions ++= allScalacOptions,
+  Test / javaOptions ++= Seq(
+    "--add-exports=java.base/sun.security.x509=ALL-UNNAMED",
+    "--add-opens=java.base/sun.security.ssl=ALL-UNNAMED"
+  ),
   Compile / doc / sources := Seq.empty,
   Compile / packageDoc / publishArtifact := false,
 )
diff --git a/examples/union-of-unions/build.sbt b/examples/union-of-unions/build.sbt
index 1a194782..0b64d38d 100644
--- a/examples/union-of-unions/build.sbt
+++ b/examples/union-of-unions/build.sbt
@@ -2,7 +2,7 @@ name := "apibuilder-union-of-unions"
 
 organization := "io.apibuilder.generator"
 
-ThisBuild / scalaVersion := "2.13.8"
+ThisBuild / scalaVersion := "2.13.11"
 
 lazy val generated = project
   .in(file("generated"))
diff --git a/go-generator/src/main/scala/models/ImportBuilder.scala b/go-generator/src/main/scala/models/ImportBuilder.scala
index 1a396767..38f3d176 100644
--- a/go-generator/src/main/scala/models/ImportBuilder.scala
+++ b/go-generator/src/main/scala/models/ImportBuilder.scala
@@ -40,7 +40,7 @@ private[models] case class ImportBuilder(importMappings: Option[String]) {
 
   // Build a list of go imports as we use them so we only import
   // libraries we actually use
-  private[this] var importPaths = mutable.ListBuffer[ImportPath]()
+  private[this] val importPaths = mutable.ListBuffer[ImportPath]()
 
   /**
     * Ensures that this library is being imported, returning the alias
diff --git a/java-generator/src/main/scala/models/generator/JavaDatatype.scala b/java-generator/src/main/scala/models/generator/JavaDatatype.scala
index eb15d22f..d3215b4f 100644
--- a/java-generator/src/main/scala/models/generator/JavaDatatype.scala
+++ b/java-generator/src/main/scala/models/generator/JavaDatatype.scala
@@ -1,11 +1,10 @@
 package models.generator
 
-import java.util.UUID
-
-import scala.annotation.nowarn
+import lib.{Datatype, Text}
 import org.joda.time.format.ISODateTimeFormat.dateTimeParser
 import play.api.libs.json._
-import lib.{Datatype, Text}
+
+import java.util.UUID
 
 sealed trait JavaDatatype {
   def apidocType: String
@@ -25,7 +24,7 @@ sealed trait JavaDatatype {
 
   def valueFromString(value: String): String = valueFromJson(Json.parse(value))
 
-  def valueFromJson(@nowarn json: JsValue): String = {
+  def valueFromJson(json: JsValue): String = {
     throw new UnsupportedOperationException(s"Unable to create default value for type $name")
   }
 }
diff --git a/lib/src/main/scala/VersionTag.scala b/lib/src/main/scala/VersionTag.scala
index 599eed0f..68c8713e 100644
--- a/lib/src/main/scala/VersionTag.scala
+++ b/lib/src/main/scala/VersionTag.scala
@@ -64,7 +64,7 @@ case class VersionTag(version: String) extends Ordered[VersionTag] {
       case 1 => {
         val pieces = splitOnDot(version)
         if (pieces.forall(s => VersionTag.isDigit(s))) {
-          Some((Seq(pieces.last.toInt + 1) ++ pieces.reverse.drop(1)).reverse.mkString("."))
+          Some((Seq(pieces.last.toInt + 1).map(_.toString) ++ pieces.reverse.drop(1)).reverse.mkString("."))
         } else {
           None
         }
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 2f8ea100..f33bd14c 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -7,6 +7,4 @@ resolvers += "Typesafe repository" at "https://repo.typesafe.com/typesafe/releas
 // Use the Play sbt plugin for Play projects
 addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.8.5")
 
-addSbtPlugin("org.scoverage"    %% "sbt-scoverage"  % "1.9.3")
-
 addSbtPlugin("io.github.davidgregory084" % "sbt-tpolecat" % "0.1.17")
diff --git a/scala-generator/src/main/scala/models/generator/ScalaClientMethodConfig.scala b/scala-generator/src/main/scala/models/generator/ScalaClientMethodConfig.scala
index ebba0f5e..0fce34a4 100644
--- a/scala-generator/src/main/scala/models/generator/ScalaClientMethodConfig.scala
+++ b/scala-generator/src/main/scala/models/generator/ScalaClientMethodConfig.scala
@@ -1,7 +1,5 @@
 package scala.generator
 
-import scala.annotation.nowarn
-
 import scala.models.{Attributes, ResponseConfig}
 
 sealed trait ScalaClientMethodConfig {
@@ -102,9 +100,9 @@ sealed trait ScalaClientMethodConfig {
 
   def asyncTypeConstraint: String = "Sync"
 
-  def asyncTypeParam(@nowarn constraint: Option[String] = None): Option[String] = None
+  def asyncTypeParam(constraint: Option[String] = None): Option[String] = None
 
-  def wrappedAsyncType(@nowarn instance: String = ""): Option[String] = None
+  def wrappedAsyncType(instance: String = ""): Option[String] = None
 
   def asyncSuccessInvoke: String = wrappedAsyncType(asyncTypeConstraint).getOrElse(asyncType) + "." + asyncSuccess
 
diff --git a/scala-generator/src/main/scala/models/generator/ScalaDatatype.scala b/scala-generator/src/main/scala/models/generator/ScalaDatatype.scala
index 33907e29..7780cb74 100644
--- a/scala-generator/src/main/scala/models/generator/ScalaDatatype.scala
+++ b/scala-generator/src/main/scala/models/generator/ScalaDatatype.scala
@@ -6,7 +6,6 @@ import lib.Text.{appendSpace, initLowerCase}
 import play.api.libs.json._
 
 import java.util.UUID
-import scala.annotation.nowarn
 import scala.util.{Failure, Success, Try}
 
 sealed trait ScalaDatatype {
@@ -42,7 +41,7 @@ sealed trait ScalaDatatype {
     }
   }
 
-  protected def default(@nowarn json: JsValue): String = {
+  protected def default(json: JsValue): String = {
     throw new UnsupportedOperationException(s"default for type ${name}")
   }
 
diff --git a/scala-generator/src/test/scala/models/play/Play26GeneratorSpec.scala b/scala-generator/src/test/scala/models/play/Play26GeneratorSpec.scala
index 541550df..0d843996 100644
--- a/scala-generator/src/test/scala/models/play/Play26GeneratorSpec.scala
+++ b/scala-generator/src/test/scala/models/play/Play26GeneratorSpec.scala
@@ -10,7 +10,7 @@ import scala.models.play.Helpers.compareWithoutWhiteSpaces
 
 class Play26GeneratorSpec extends AnyFunSpec with Matchers with ScalaCheckPropertyChecks {
 
-  implicit val scalacheckConfig = generatorDrivenConfig.copy(sizeRange = 10)
+  private implicit val scalacheckConfig: PropertyCheckConfiguration = generatorDrivenConfig.copy(sizeRange = 10)
 
   it("prependHeader should prepend a header") {
     forAll { (header: String, contents: String, form: InvocationForm) =>