diff --git a/README.md b/README.md
index f226a04..ba7cf90 100644
--- a/README.md
+++ b/README.md
@@ -167,6 +167,10 @@ val optValue: Option[T] = decrypter.reads(encryptedValue).asOpt.map(_.decryptedV
 
 ## Changes
 
+### Version 8.0.0
+
+Built for Scala 3 and Scala 2.13 - drops Scala 2.12.
+
 ### Version 7.6.0
 
 Adds support for Play 2.9 and Play 3.0
diff --git a/build.sbt b/build.sbt
index 81aba32..4fe9863 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,7 +1,7 @@
-val scala2_12 = "2.12.18"
 val scala2_13 = "2.13.12"
+val scala3    = "3.3.3"
 
-ThisBuild / majorVersion     := 7
+ThisBuild / majorVersion     := 8
 ThisBuild / scalaVersion     := scala2_13
 ThisBuild / isPublicArtefact := true
 ThisBuild / scalacOptions    ++= Seq("-feature")
@@ -17,7 +17,7 @@ lazy val library = Project("library", file("."))
 
 lazy val crypto = Project("crypto", file("crypto"))
   .settings(
-    crossScalaVersions := Seq(scala2_12, scala2_13),
+    crossScalaVersions := Seq(scala2_13, scala3),
     libraryDependencies ++= LibDependencies.cryptoCompile ++ LibDependencies.cryptoTest
   )
 
@@ -30,7 +30,7 @@ def shareSources(location: String) = Seq(
 
 lazy val cryptoJsonPlay28 = Project("crypto-json-play-28", file("crypto-json-play-28"))
   .settings(
-    crossScalaVersions := Seq(scala2_12, scala2_13),
+    crossScalaVersions := Seq(scala2_13),
     shareSources("crypto-json"),
     libraryDependencies ++= LibDependencies.cryptoJsonPlay28Compile ++ LibDependencies.cryptoTest
   ).dependsOn(crypto)
@@ -44,7 +44,7 @@ lazy val cryptoJsonPlay29 = Project("crypto-json-play-29", file("crypto-json-pla
 
 lazy val cryptoJsonPlay30 = Project("crypto-json-play-30", file("crypto-json-play-30"))
   .settings(
-    crossScalaVersions := Seq(scala2_13),
+    crossScalaVersions := Seq(scala2_13, scala3),
     shareSources("crypto-json"),
     libraryDependencies ++= LibDependencies.cryptoJsonPlay30Compile ++ LibDependencies.cryptoTest
   ).dependsOn(crypto)
diff --git a/crypto-json/src/main/scala/uk/gov/hmrc/crypto/json/CryptoFormats.scala b/crypto-json/src/main/scala/uk/gov/hmrc/crypto/json/CryptoFormats.scala
index eda2df0..2e37d2f 100644
--- a/crypto-json/src/main/scala/uk/gov/hmrc/crypto/json/CryptoFormats.scala
+++ b/crypto-json/src/main/scala/uk/gov/hmrc/crypto/json/CryptoFormats.scala
@@ -25,5 +25,5 @@ object CryptoFormats {
   val encryptedValueFormat: Format[EncryptedValue] =
     ( (__ \ "value").format[String]
     ~ (__ \ "nonce").format[String]
-    )(EncryptedValue.apply, unlift(EncryptedValue.unapply))
+    )(EncryptedValue.apply, ev => (ev.value, ev.nonce))
 }
diff --git a/crypto-json/src/test/scala/uk/gov/hmrc/crypto/json/JsonEncryptionSpec.scala b/crypto-json/src/test/scala/uk/gov/hmrc/crypto/json/JsonEncryptionSpec.scala
index 3db4f7c..53846eb 100644
--- a/crypto-json/src/test/scala/uk/gov/hmrc/crypto/json/JsonEncryptionSpec.scala
+++ b/crypto-json/src/test/scala/uk/gov/hmrc/crypto/json/JsonEncryptionSpec.scala
@@ -84,7 +84,8 @@ class CryptoFormatsSpec
 }
 
 object CryptoFormatsSpec {
-  implicit val crypto = SymmetricCryptoFactory.aesCrypto("P5xsJ9Nt+quxGZzB4DeLfw==")
+  implicit val crypto: Encrypter with Decrypter =
+    SymmetricCryptoFactory.aesCrypto("P5xsJ9Nt+quxGZzB4DeLfw==")
 
   case class SensitiveTestEntity(
     normalString    : String,
@@ -94,7 +95,7 @@ object CryptoFormatsSpec {
   )
 
   object SensitiveTestEntity {
-    implicit val formats = {
+    implicit val formats: Format[SensitiveTestEntity] = {
       implicit val sensitiveStringCrypto    : Format[SensitiveString]     = JsonEncryption.sensitiveEncrypterDecrypter(SensitiveString.apply)
       implicit val sensitiveBooleanCrypto   : Format[SensitiveBoolean]    = JsonEncryption.sensitiveEncrypterDecrypter(SensitiveBoolean.apply)
       implicit val sensitiveBigDecimalCrypto: Format[SensitiveBigDecimal] = JsonEncryption.sensitiveEncrypterDecrypter(SensitiveBigDecimal.apply)
@@ -110,7 +111,8 @@ object CryptoFormatsSpec {
   )
 
   object TestForm {
-    implicit val formats = Json.format[TestForm]
+    implicit val formats: Format[TestForm] =
+      Json.format[TestForm]
   }
 
   case class SensitiveTestForm(override val decryptedValue: TestForm) extends Sensitive[TestForm]
diff --git a/crypto/src/main/scala/uk/gov/hmrc/crypto/AesCrypto.scala b/crypto/src/main/scala/uk/gov/hmrc/crypto/AesCrypto.scala
index ff2e78d..27909d8 100644
--- a/crypto/src/main/scala/uk/gov/hmrc/crypto/AesCrypto.scala
+++ b/crypto/src/main/scala/uk/gov/hmrc/crypto/AesCrypto.scala
@@ -38,7 +38,6 @@ trait AesCrypto extends Encrypter with Decrypter {
     plain match {
       case PlainBytes(bytes) => Crypted(encrypter.encrypt(bytes))
       case PlainText(text)   => Crypted(encrypter.encrypt(text))
-      case _                 => throw new Exception(s"Unable to encrypt unkown message type: $plain")
     }
 
   override def decrypt(encrypted: Crypted): PlainText =
diff --git a/crypto/src/main/scala/uk/gov/hmrc/crypto/AesGCMCrypto.scala b/crypto/src/main/scala/uk/gov/hmrc/crypto/AesGCMCrypto.scala
index ca450ad..7b347e1 100644
--- a/crypto/src/main/scala/uk/gov/hmrc/crypto/AesGCMCrypto.scala
+++ b/crypto/src/main/scala/uk/gov/hmrc/crypto/AesGCMCrypto.scala
@@ -40,7 +40,6 @@ trait AesGCMCrypto extends Encrypter with Decrypter {
     plain match {
       case PlainBytes(bytes) => Crypted(fromEncryptedValue(crypto.encrypt(bytes        , emptyAssociatedData)))
       case PlainText(text)   => Crypted(fromEncryptedValue(crypto.encrypt(text.getBytes, emptyAssociatedData)))
-      case _                 => throw new RuntimeException(s"Unable to encrypt unknown message type: $plain")
     }
 
   private def fromEncryptedValue(ev: EncryptedBytes): String = {
diff --git a/crypto/src/main/scala/uk/gov/hmrc/crypto/CompositeSymmetricCrypto.scala b/crypto/src/main/scala/uk/gov/hmrc/crypto/CompositeSymmetricCrypto.scala
index 87d68a4..ad8257e 100644
--- a/crypto/src/main/scala/uk/gov/hmrc/crypto/CompositeSymmetricCrypto.scala
+++ b/crypto/src/main/scala/uk/gov/hmrc/crypto/CompositeSymmetricCrypto.scala
@@ -35,7 +35,7 @@ trait CompositeSymmetricCrypto extends Encrypter with Decrypter {
     decrypt(d => Try(d.decryptAsBytes(scrambled)))
 
   private def decrypt[T <: PlainContent](tryDecryption: Decrypter => Try[T]): T = {
-    val decrypterStream = (currentCrypto +: previousCryptos).toStream
+    val decrypterStream = (currentCrypto +: previousCryptos).to(LazyList)
 
     val message =
       decrypterStream
diff --git a/crypto/src/main/scala/uk/gov/hmrc/crypto/SymmetricCryptoFactory.scala b/crypto/src/main/scala/uk/gov/hmrc/crypto/SymmetricCryptoFactory.scala
index b7b1a83..b881033 100644
--- a/crypto/src/main/scala/uk/gov/hmrc/crypto/SymmetricCryptoFactory.scala
+++ b/crypto/src/main/scala/uk/gov/hmrc/crypto/SymmetricCryptoFactory.scala
@@ -37,7 +37,7 @@ object SymmetricCryptoFactory {
         decrypt(d => Try(d.decryptAsBytes(scrambled)))
 
       private def decrypt[T <: PlainContent](tryDecryption: Decrypter => Try[T]): T = {
-        val decrypterStream = (currentCrypto +: previousDecrypters).toStream
+        val decrypterStream = (currentCrypto +: previousDecrypters).to(LazyList)
         decrypterStream
           .map(tryDecryption)
           .collectFirst { case Success(msg) => msg }
@@ -95,7 +95,7 @@ object SymmetricCryptoFactory {
         currentCrypto.encrypt(valueToEncrypt, associatedText)
 
       override def decrypt(valueToDecrypt: EncryptedValue, associatedText: String): String = {
-        val decrypterStream = (currentCrypto +: previousDecrypters).toStream
+        val decrypterStream = (currentCrypto +: previousDecrypters).to(LazyList)
         decrypterStream
           .map(crypter => Try(crypter.decrypt(valueToDecrypt, associatedText)))
           .collectFirst { case Success(msg) => msg }
diff --git a/crypto/src/main/scala/uk/gov/hmrc/crypto/ValueFinder.scala b/crypto/src/main/scala/uk/gov/hmrc/crypto/ValueFinder.scala
index 51c17ce..0dde912 100644
--- a/crypto/src/main/scala/uk/gov/hmrc/crypto/ValueFinder.scala
+++ b/crypto/src/main/scala/uk/gov/hmrc/crypto/ValueFinder.scala
@@ -17,7 +17,7 @@
 package uk.gov.hmrc.crypto
 
 import com.typesafe.config.Config
-import collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 
 import scala.util.Try
 
diff --git a/crypto/src/test/scala/uk/gov/hmrc/crypto/ApplicationCryptoSpec.scala b/crypto/src/test/scala/uk/gov/hmrc/crypto/ApplicationCryptoSpec.scala
index 7415a5d..8e5e42d 100644
--- a/crypto/src/test/scala/uk/gov/hmrc/crypto/ApplicationCryptoSpec.scala
+++ b/crypto/src/test/scala/uk/gov/hmrc/crypto/ApplicationCryptoSpec.scala
@@ -20,7 +20,7 @@ import com.typesafe.config.ConfigFactory
 import org.scalatest.matchers.should.Matchers
 import org.scalatest.wordspec.AnyWordSpecLike
 
-import collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 
 class ApplicationCryptoSpec extends AnyWordSpecLike with Matchers {
 
diff --git a/crypto/src/test/scala/uk/gov/hmrc/crypto/CompositeOneWayCryptoSpec.scala b/crypto/src/test/scala/uk/gov/hmrc/crypto/CompositeOneWayCryptoSpec.scala
index e0e8a66..59d8712 100644
--- a/crypto/src/test/scala/uk/gov/hmrc/crypto/CompositeOneWayCryptoSpec.scala
+++ b/crypto/src/test/scala/uk/gov/hmrc/crypto/CompositeOneWayCryptoSpec.scala
@@ -17,12 +17,12 @@
 package uk.gov.hmrc.crypto
 
 import com.typesafe.config.ConfigFactory
-import org.mockito.MockitoSugar
 import org.scalatest.matchers.should.Matchers
 import org.scalatest.wordspec.AnyWordSpecLike
+import org.scalatestplus.mockito.MockitoSugar
 
 import java.util.Base64
-import scala.collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 
 @annotation.nowarn("msg=deprecated")
 class CompositeOneWayCryptoSpec extends AnyWordSpecLike with Matchers with MockitoSugar {
diff --git a/crypto/src/test/scala/uk/gov/hmrc/crypto/CryptoGCMWithKeysFromConfigSpec.scala b/crypto/src/test/scala/uk/gov/hmrc/crypto/CryptoGCMWithKeysFromConfigSpec.scala
index 8f735d3..098ee0a 100644
--- a/crypto/src/test/scala/uk/gov/hmrc/crypto/CryptoGCMWithKeysFromConfigSpec.scala
+++ b/crypto/src/test/scala/uk/gov/hmrc/crypto/CryptoGCMWithKeysFromConfigSpec.scala
@@ -17,13 +17,13 @@
 package uk.gov.hmrc.crypto
 
 import com.typesafe.config.ConfigFactory
-import org.mockito.MockitoSugar
 import org.scalatest.matchers.should.Matchers
 import org.scalatest.wordspec.AnyWordSpecLike
+import org.scalatestplus.mockito.MockitoSugar
 
 import java.security.SecureRandom
 import java.util.Base64
-import collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 
 @annotation.nowarn("msg=deprecated")
 class CryptoGCMWithKeysFromConfigSpec extends AnyWordSpecLike with Matchers with MockitoSugar {
diff --git a/crypto/src/test/scala/uk/gov/hmrc/crypto/CryptoWithKeysFromConfigSpec.scala b/crypto/src/test/scala/uk/gov/hmrc/crypto/CryptoWithKeysFromConfigSpec.scala
index 9120dcf..f6de568 100644
--- a/crypto/src/test/scala/uk/gov/hmrc/crypto/CryptoWithKeysFromConfigSpec.scala
+++ b/crypto/src/test/scala/uk/gov/hmrc/crypto/CryptoWithKeysFromConfigSpec.scala
@@ -17,12 +17,12 @@
 package uk.gov.hmrc.crypto
 
 import com.typesafe.config.ConfigFactory
-import org.mockito.MockitoSugar
 import org.scalatest.matchers.should.Matchers
 import org.scalatest.wordspec.AnyWordSpecLike
+import org.scalatestplus.mockito.MockitoSugar
 
 import java.util.Base64
-import collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 
 @annotation.nowarn("msg=deprecated")
 class CryptoWithKeysFromConfigSpec extends AnyWordSpecLike with Matchers with MockitoSugar {
diff --git a/project/LibDependencies.scala b/project/LibDependencies.scala
index d6f2d36..7ddfe58 100644
--- a/project/LibDependencies.scala
+++ b/project/LibDependencies.scala
@@ -11,18 +11,18 @@ object LibDependencies {
     "org.scalatest"        %% "scalatest"       % "3.2.17"   % Test,
     "com.vladsch.flexmark" %  "flexmark-all"    % "0.64.8"   % Test,
     "org.scalatestplus"    %% "scalacheck-1-17" % "3.2.17.0" % Test,
-    "org.mockito"          %% "mockito-scala"   % "1.17.29"  % Test
+    "org.scalatestplus"    %% "mockito-3-4"     % "3.2.10.0" % Test
   )
 
   val cryptoJsonPlay28Compile = Seq(
-    "com.typesafe.play" %% "play-json" % "2.8.1" // version provided by Play 2.8
+    "com.typesafe.play" %% "play-json" % "2.8.2" // version provided by Play 2.8
   )
 
   val cryptoJsonPlay29Compile = Seq(
-    "com.typesafe.play" %% "play-json" % "2.10.2" // version provided by Play 2.9
+    "com.typesafe.play" %% "play-json" % "2.10.5" // version provided by Play 2.9
   )
 
   val cryptoJsonPlay30Compile = Seq(
-    "org.playframework" %% "play-json" % "3.0.0" // version provided by Play 3.0
+    "org.playframework" %% "play-json" % "3.0.3" // version provided by Play 3.0
   )
 }
diff --git a/project/build.properties b/project/build.properties
index e8a1e24..04267b1 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -1 +1 @@
-sbt.version=1.9.7
+sbt.version=1.9.9
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 993acb0..e8fc669 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -1,4 +1,4 @@
 resolvers += MavenRepository("HMRC-open-artefacts-maven2", "https://open.artefacts.tax.service.gov.uk/maven2")
 resolvers += Resolver.url("HMRC-open-artefacts-ivy2", url("https://open.artefacts.tax.service.gov.uk/ivy2"))(Resolver.ivyStylePatterns)
 
-addSbtPlugin("uk.gov.hmrc" % "sbt-auto-build" % "3.15.0")
+addSbtPlugin("uk.gov.hmrc" % "sbt-auto-build" % "3.21.0")