diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c9eed7d..d19c616 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,10 +13,9 @@ jobs:
       - uses: actions/checkout@v4
       - id: set-scala-versions
         run: |
-          scala212=$(grep "scala2.12" project/Dependencies.scala | sed -E 's/.*= //')
           scala213=$(grep "scala2.13" project/Dependencies.scala | sed -E 's/.*= //')
           scala3=$(grep "scala3" project/Dependencies.scala | sed -E 's/.*= //')
-          echo "versions={\"scala\": [${scala212}, ${scala213}, ${scala3}]}" >> $GITHUB_OUTPUT
+          echo "versions={\"scala\": [${scala213}, ${scala3}]}" >> $GITHUB_OUTPUT
   build:
     needs:
       - setup
diff --git a/build.sbt b/build.sbt
index b1f8930..eb48f26 100644
--- a/build.sbt
+++ b/build.sbt
@@ -19,7 +19,7 @@ lazy val mess = project
           )
         ),
         scalaVersion       := Ver.`scala2.13`,
-        crossScalaVersions := Seq(Ver.`scala2.12`, Ver.`scala2.13`, Ver.scala3),
+        crossScalaVersions := Seq(Ver.`scala2.13`, Ver.scala3),
         libraryDependencies ++= Seq(MunitScalacheck).map(_ % Test),
         testFrameworks += new TestFramework("munit.Framework"),
         scalafmtOnCompile := true,
diff --git a/modules/core/src/main/scala_2.12-/mess/codec/AutoOps.scala b/modules/core/src/main/scala_2.12-/mess/codec/AutoOps.scala
deleted file mode 100644
index d08f137..0000000
--- a/modules/core/src/main/scala_2.12-/mess/codec/AutoOps.scala
+++ /dev/null
@@ -1,8 +0,0 @@
-package mess.codec
-
-import shapeless.Lazy
-
-private[codec] trait AutoOps {
-  implicit def autoDerivedEncoder[A](implicit A: Lazy[DerivedEncoder[A]]): Encoder.AsMap[A] = A.value
-  implicit def autoDerivedDecoder[A](implicit A: Lazy[DerivedDecoder[A]]): Decoder[A]       = A.value
-}
diff --git a/modules/core/src/main/scala_2.12-/mess/codec/DerivedDecoder1.scala b/modules/core/src/main/scala_2.12-/mess/codec/DerivedDecoder1.scala
deleted file mode 100644
index 15db230..0000000
--- a/modules/core/src/main/scala_2.12-/mess/codec/DerivedDecoder1.scala
+++ /dev/null
@@ -1,32 +0,0 @@
-package mess.codec
-
-import shapeless._
-import shapeless.labelled._
-
-private[codec] trait DerivedDecoder1 extends DerivedDecoder2 { self: DerivedDecoderOps =>
-  implicit final def decodeGen[A, R](implicit
-    gen: LabelledGeneric.Aux[A, R],
-    decodeR: Lazy[DerivedDecoder[R]]
-  ): DerivedDecoder[A] = decodeGenInternal(gen, decodeR.value)
-}
-
-private[codec] trait DerivedDecoder2 extends DerivedDecoder3 { self: DerivedDecoderOps =>
-  implicit final val decodeHNil: DerivedDecoder[HNil] = _ => Right(HNil)
-
-  implicit final def decodeLabelledHList[K <: Symbol, H, T <: HList](implicit
-    witK: Witness.Aux[K],
-    decodeH: Decoder[H],
-    decodeT: Lazy[DerivedDecoder[T]]
-  ): DerivedDecoder[FieldType[K, H] :: T] = self.decodeLabelledHListInternal(witK, decodeH, decodeT.value)
-}
-
-private[codec] trait DerivedDecoder3 { self: DerivedDecoderOps =>
-  implicit final val decodeCNil: DerivedDecoder[CNil] =
-    m => Left(TypeMismatchError("Sum", m))
-
-  implicit final def decodeLabelledCoproduct[K <: Symbol, L, R <: Coproduct](implicit
-    witK: Witness.Aux[K],
-    decodeL: Lazy[DerivedDecoder[L]],
-    decodeR: Lazy[DerivedDecoder[R]]
-  ): DerivedDecoder[FieldType[K, L] :+: R] = decodeLabelledCoproductInternal(witK, decodeL.value, decodeR.value)
-}
diff --git a/modules/core/src/main/scala_2.12-/mess/codec/DerivedEncoder1.scala b/modules/core/src/main/scala_2.12-/mess/codec/DerivedEncoder1.scala
deleted file mode 100644
index 9a68ed2..0000000
--- a/modules/core/src/main/scala_2.12-/mess/codec/DerivedEncoder1.scala
+++ /dev/null
@@ -1,35 +0,0 @@
-package mess.codec
-
-import mess.Fmt
-import shapeless._
-import shapeless.labelled._
-
-private[codec] trait DerivedEncoder1 extends DerivedEncoder2 { self: DerivedEncoderOps =>
-  implicit final def encodeGen[A, R](implicit
-    gen: LabelledGeneric.Aux[A, R],
-    encodeR: Lazy[DerivedEncoder[R]]
-  ): DerivedEncoder[A] = encodeGenInternal(gen, encodeR.value)
-}
-
-private[codec] trait DerivedEncoder2 extends DerivedEncoder3 { self: DerivedEncoderOps =>
-  implicit final val encodeHNil: DerivedEncoder[HNil] =
-    _ => Fmt.MMap.newBuilder
-
-  implicit final def encodeLabelledHList[K <: Symbol, H, T <: HList](implicit
-    witK: Witness.Aux[K],
-    encodeK: Encoder[K],
-    encodeH: Encoder[H],
-    encodeT: Lazy[DerivedEncoder[T]]
-  ): DerivedEncoder[FieldType[K, H] :: T] = encodeLabelledHListInternal(witK, encodeK, encodeH, encodeT.value)
-}
-
-private[codec] trait DerivedEncoder3 { self: DerivedEncoderOps =>
-  implicit final val encodeCNil: DerivedEncoder[CNil] =
-    _ => sys.error("Cannot encode CNil")
-
-  implicit final def encodeLabelledCCons[K <: Symbol, L, R <: Coproduct](implicit
-    witK: Witness.Aux[K],
-    encodeL: Lazy[DerivedEncoder[L]],
-    encodeR: Lazy[DerivedEncoder[R]]
-  ): DerivedEncoder[FieldType[K, L] :+: R] = encodeLabelledCConsInternal(witK, encodeL.value, encodeR.value)
-}
diff --git a/modules/core/src/main/scala_2.12-/mess/codec/SemiautoOps.scala b/modules/core/src/main/scala_2.12-/mess/codec/SemiautoOps.scala
deleted file mode 100644
index 2494d34..0000000
--- a/modules/core/src/main/scala_2.12-/mess/codec/SemiautoOps.scala
+++ /dev/null
@@ -1,8 +0,0 @@
-package mess.codec
-
-import shapeless.Lazy
-
-private[codec] trait SemiautoOps {
-  def derivedEncoder[A](implicit A: Lazy[DerivedEncoder[A]]): Encoder.AsMap[A] = A.value
-  def derivedDecoder[A](implicit A: Lazy[DerivedDecoder[A]]): Decoder[A]       = A.value
-}
diff --git a/modules/core/src/main/scala_2.12-/mess/internal/ScalaVersionSpecifics.scala b/modules/core/src/main/scala_2.12-/mess/internal/ScalaVersionSpecifics.scala
deleted file mode 100644
index 226e6bb..0000000
--- a/modules/core/src/main/scala_2.12-/mess/internal/ScalaVersionSpecifics.scala
+++ /dev/null
@@ -1,12 +0,0 @@
-package mess.internal
-
-import scala.collection.generic.CanBuildFrom
-import scala.collection.mutable
-
-private[mess] object ScalaVersionSpecifics {
-  private[mess] type Factory[-E, +T] = CanBuildFrom[Nothing, E, T]
-
-  implicit private[mess] class FactoryOps[F, E, T](val bf: Factory[E, T]) extends AnyVal {
-    def newBuilder: mutable.Builder[E, T] = bf.apply()
-  }
-}
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 0bebccd..70033a8 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -4,7 +4,6 @@ object Dependencies {
   val Ver = new {
     val scala3      = "3.4.2"
     val `scala2.13` = "2.13.14"
-    val `scala2.12` = "2.12.19"
 
     val shapeless   = "2.3.12"
     val msgpackJava = "0.9.8"