diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index 55c94aa06..6d67bf18e 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -21,7 +21,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        SCALA_VERSION: [2.12, 2.13, 3]
+        SCALA_VERSION: [2.13, 3]
         JDK: [17, 21]
         PEKKO_VERSION: ['default']
     steps:
diff --git a/.github/workflows/validate-and-test.yml b/.github/workflows/validate-and-test.yml
index 05b1fe2bf..9ffb326f0 100644
--- a/.github/workflows/validate-and-test.yml
+++ b/.github/workflows/validate-and-test.yml
@@ -70,7 +70,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        SCALA_VERSION: [2.12, 2.13, 3.3]
+        SCALA_VERSION: [2.13, 3.3]
         JDK: [17]
     steps:
       - name: Checkout
diff --git a/LICENSE b/LICENSE
index 5782dafd8..bbc10fd00 100644
--- a/LICENSE
+++ b/LICENSE
@@ -212,8 +212,8 @@ Copyright 2014 Twitter, Inc.
 
 pekko-http-core contains code from scala-collection-compat in the `org.apache.pekko.http.ccompat` package
 distributed under the Apache 2.0 license.
-- http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/package.scala
-- http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/CompatImpl.scala
+- http-core/src/main/scala-2.13/org/apache/pekko/http/ccompat/package.scala
+- http-core/src/main/scala-2.13/org/apache/pekko/http/ccompat/CompatImpl.scala
 
 Copyright EPFL and Lightbend, Inc.
 
diff --git a/build.sbt b/build.sbt
index 55e8e4c16..0f75cb85e 100644
--- a/build.sbt
+++ b/build.sbt
@@ -88,40 +88,17 @@ lazy val root = Project(
     Compile / headerCreate / unmanagedSources := (baseDirectory.value / "project").**("*.scala").get)
   .aggregate(aggregatedProjects: _*)
 
-/**
- * Adds a `src/.../scala-2.13+` source directory for Scala 2.13 and newer
- * and a `src/.../scala-2.13-` source directory for Scala version older than 2.13
- */
-def add213CrossDirs(config: Configuration): Seq[Setting[_]] = Seq(
-  config / unmanagedSourceDirectories += {
-    val sourceDir = (config / sourceDirectory).value
-    CrossVersion.partialVersion(scalaVersion.value) match {
-      case Some((e, n)) if e > 2 || (e == 2 && n >= 13) => sourceDir / "scala-2.13+"
-      case _                                            => sourceDir / "scala-2.13-"
-    }
-  })
-
-val commonSettings =
-  add213CrossDirs(Compile) ++
-  add213CrossDirs(Test)
-
 val scalaMacroSupport = Seq(
   scalacOptions ++= {
     CrossVersion.partialVersion(scalaVersion.value) match {
-      case Some((2, n)) if n >= 13 =>
+      case Some((2, n)) =>
         Seq("-Ymacro-annotations")
       case _ =>
         Seq.empty
     }
-  },
-  libraryDependencies ++= (CrossVersion.partialVersion(scalaVersion.value) match {
-    case Some((2, n)) if n < 13 =>
-      Seq(compilerPlugin(("org.scalamacros" % "paradise" % "2.1.1").cross(CrossVersion.full)))
-    case _ => Seq.empty
-  }))
+  })
 
 lazy val parsing = project("parsing")
-  .settings(commonSettings)
   .settings(AutomaticModuleName.settings("pekko.http.parsing"))
   .addPekkoModuleDependency("pekko-actor", "provided", PekkoCoreDependency.default)
   .settings(Dependencies.parsing)
@@ -132,7 +109,6 @@ lazy val parsing = project("parsing")
   .disablePlugins(MimaPlugin)
 
 lazy val httpCore = project("http-core")
-  .settings(commonSettings)
   .settings(AutomaticModuleName.settings("pekko.http.core"))
   .settings(AddMetaInfLicenseFiles.httpCoreSettings)
   .dependsOn(parsing /*, httpScalafixRules % ScalafixConfig*/ )
@@ -146,13 +122,9 @@ lazy val httpCore = project("http-core")
   .settings(scalaMacroSupport)
   .enablePlugins(BootstrapGenjavadoc)
   .enablePlugins(ReproducibleBuildsPlugin)
-  .enablePlugins(Pre213Preprocessor).settings(
-    Pre213Preprocessor.pre213Files := Seq(
-      "headers.scala", "HttpMessage.scala", "LanguageRange.scala", "CacheDirective.scala", "LinkValue.scala"))
   .disablePlugins(ScalafixPlugin)
 
 lazy val http = project("http")
-  .settings(commonSettings)
   .settings(AutomaticModuleName.settings("pekko.http"))
   .dependsOn(httpCore)
   .addPekkoModuleDependency("pekko-stream", "provided", PekkoCoreDependency.default)
@@ -160,14 +132,10 @@ lazy val http = project("http")
   .settings(
     Compile / scalacOptions += "-language:_")
   .settings(scalaMacroSupport)
-  .enablePlugins(Pre213Preprocessor).settings(
-    Pre213Preprocessor.pre213Files := Seq(
-      "scaladsl/server/directives/FormFieldDirectives.scala", "scaladsl/server/directives/RespondWithDirectives.scala"))
   .enablePlugins(BootstrapGenjavadoc, BoilerplatePlugin)
   .enablePlugins(ReproducibleBuildsPlugin)
 
 lazy val http2Tests = project("http2-tests")
-  .settings(commonSettings)
   .settings(AutomaticModuleName.settings("pekko.http.http2"))
   .dependsOn(httpCore, httpTestkit % "test", httpCore % "test->test")
   .addPekkoModuleDependency("pekko-stream", "provided", PekkoCoreDependency.default)
@@ -209,7 +177,6 @@ lazy val http2Tests = project("http2-tests")
   .disablePlugins(MimaPlugin) // experimental module still
 
 lazy val httpTestkit = project("http-testkit")
-  .settings(commonSettings)
   .settings(AutomaticModuleName.settings("pekko.http.testkit"))
   .dependsOn(http)
   .addPekkoModuleDependency("pekko-stream-testkit", "provided", PekkoCoreDependency.default)
@@ -225,7 +192,6 @@ lazy val httpTestkit = project("http-testkit")
   .disablePlugins(MimaPlugin) // testkit, no bin compat guaranteed
 
 lazy val httpTestkitMunit = project("http-testkit-munit")
-  .settings(commonSettings)
   .settings(AutomaticModuleName.settings("pekko.http.testkit.munit"))
   .dependsOn(http, httpTestkit)
   .addPekkoModuleDependency("pekko-stream-testkit", "provided", PekkoCoreDependency.default)
@@ -234,7 +200,6 @@ lazy val httpTestkitMunit = project("http-testkit-munit")
   .disablePlugins(MimaPlugin) // testkit, no bin compat guaranteed
 
 lazy val httpTests = project("http-tests")
-  .settings(commonSettings)
   .settings(Dependencies.httpTests)
   .dependsOn(httpSprayJson, httpXml, httpJackson,
     httpTestkit % "test", httpCore % "test->test",
@@ -261,7 +226,6 @@ lazy val httpTests = project("http-tests")
     })
 
 lazy val httpJmhBench = project("http-bench-jmh")
-  .settings(commonSettings)
   .dependsOn(http, httpCors, http2Tests % "compile->compile,test")
   .addPekkoModuleDependency("pekko-stream", "", PekkoCoreDependency.default)
   .enablePlugins(JmhPlugin)
@@ -269,7 +233,6 @@ lazy val httpJmhBench = project("http-bench-jmh")
   .disablePlugins(MimaPlugin)
 
 lazy val httpMarshallersScala = project("http-marshallers-scala")
-  .settings(commonSettings)
   .enablePlugins(NoPublish /*, AggregatePRValidation*/ )
   .disablePlugins(MimaPlugin)
   .aggregate(httpSprayJson, httpXml)
@@ -287,7 +250,6 @@ lazy val httpSprayJson =
     .settings(Dependencies.httpSprayJson)
 
 lazy val httpMarshallersJava = project("http-marshallers-java")
-  .settings(commonSettings)
   .enablePlugins(NoPublish /*, AggregatePRValidation*/ )
   .disablePlugins(MimaPlugin)
   .aggregate(httpJackson)
@@ -304,7 +266,6 @@ lazy val httpJackson =
 lazy val httpCaching = project("http-caching")
   .settings(
     name := "pekko-http-caching")
-  .settings(commonSettings)
   .settings(AutomaticModuleName.settings("pekko.http.caching"))
   .addPekkoModuleDependency("pekko-stream", "provided", PekkoCoreDependency.default)
   .addPekkoModuleDependency("pekko-stream-testkit", "provided", PekkoCoreDependency.default)
@@ -315,7 +276,6 @@ lazy val httpCaching = project("http-caching")
 lazy val httpCors = project("http-cors")
   .settings(
     name := "pekko-http-cors")
-  .settings(commonSettings)
   .settings(AutomaticModuleName.settings("pekko.http.cors"))
   .settings(AddMetaInfLicenseFiles.httpCorsSettings)
   .addPekkoModuleDependency("pekko-stream", "provided", PekkoCoreDependency.default)
@@ -335,7 +295,6 @@ def httpMarshallersScalaSubproject(moduleName: String) =
     .dependsOn(http)
     .settings(
       name := s"pekko-http-$moduleName")
-    .settings(commonSettings)
     .enablePlugins(BootstrapGenjavadoc)
     .enablePlugins(ReproducibleBuildsPlugin)
 
@@ -346,7 +305,6 @@ def httpMarshallersJavaSubproject(moduleName: String) =
     .settings(
       name := s"pekko-http-$moduleName")
     .dependsOn(http)
-    .settings(commonSettings)
     .enablePlugins(BootstrapGenjavadoc)
     .enablePlugins(ReproducibleBuildsPlugin)
 
diff --git a/http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/CompatImpl.scala b/http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/CompatImpl.scala
deleted file mode 100644
index 0e27de2c9..000000000
--- a/http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/CompatImpl.scala
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * license agreements; and to You under the Apache License, version 2.0:
- *
- *   https://www.apache.org/licenses/LICENSE-2.0
- *
- * This file is part of the Apache Pekko project, which was derived from Akka.
- */
-
-/*
- * Copyright (C) 2019-2022 Lightbend Inc. <https://www.lightbend.com>
- */
-
-/*
- * Scala (https://www.scala-lang.org)
- *
- * Copyright EPFL and Lightbend, Inc.
- *
- * Licensed under Apache License 2.0
- * (http://www.apache.org/licenses/LICENSE-2.0).
- *
- * See the NOTICE file distributed with this work for
- * additional information regarding copyright ownership.
- */
-
-package org.apache.pekko.http.ccompat
-
-import scala.collection.generic.CanBuildFrom
-import scala.collection.mutable
-
-/**
- * INTERNAL API
- *
- * Based on https://github.com/scala/scala-collection-compat/blob/main/compat/src/main/scala-2.11_2.12/scala/collection/compat/CompatImpl.scala
- * but reproduced here so we don't need to add a dependency on this library. It contains much more than we need right now, and is
- * not promising binary compatibility yet at the time of writing.
- */
-private[ccompat] object CompatImpl {
-  def simpleCBF[A, C](f: => mutable.Builder[A, C]): CanBuildFrom[Any, A, C] = new CanBuildFrom[Any, A, C] {
-    def apply(from: Any): mutable.Builder[A, C] = apply()
-    def apply(): mutable.Builder[A, C] = f
-  }
-}
diff --git a/http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/MapHelpers.scala b/http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/MapHelpers.scala
deleted file mode 100644
index b69a0fbfa..000000000
--- a/http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/MapHelpers.scala
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * license agreements; and to You under the Apache License, version 2.0:
- *
- *   https://www.apache.org/licenses/LICENSE-2.0
- *
- * This file is part of the Apache Pekko project, which was derived from Akka.
- */
-
-/*
- * Copyright (C) 2018-2022 Lightbend Inc. <https://www.lightbend.com>
- */
-
-package org.apache.pekko.http.ccompat
-
-/**
- * INTERNAL API
- */
-object MapHelpers {
-  def convertMapToScala[K, V](jmap: java.util.Map[K, V]): scala.collection.immutable.Map[K, V] = {
-    import scala.collection.JavaConverters._
-    Map.empty ++ jmap.asScala
-  }
-}
diff --git a/http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/imm/package.scala b/http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/imm/package.scala
deleted file mode 100644
index 3775d09df..000000000
--- a/http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/imm/package.scala
+++ /dev/null
@@ -1,30 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * license agreements; and to You under the Apache License, version 2.0:
- *
- *   https://www.apache.org/licenses/LICENSE-2.0
- *
- * This file is part of the Apache Pekko project, which was derived from Akka.
- */
-
-/*
- * Copyright (C) 2018-2022 Lightbend Inc. <https://www.lightbend.com>
- */
-
-package org.apache.pekko.http.ccompat
-
-import scala.collection.immutable
-
-/**
- * INTERNAL API
- */
-package object imm {
-  implicit class SortedSetOps[A](val real: immutable.SortedSet[A]) extends AnyVal {
-    def unsorted: immutable.Set[A] = real
-  }
-
-  implicit class StreamOps[A](val underlying: immutable.Stream[A]) extends AnyVal {
-    // renamed in 2.13
-    def lazyAppendedAll[B >: A](rest: => TraversableOnce[B]): Stream[B] = underlying.append(rest)
-  }
-}
diff --git a/http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/package.scala b/http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/package.scala
deleted file mode 100644
index 478ca1f19..000000000
--- a/http-core/src/main/scala-2.13-/org/apache/pekko/http/ccompat/package.scala
+++ /dev/null
@@ -1,74 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * license agreements; and to You under the Apache License, version 2.0:
- *
- *   https://www.apache.org/licenses/LICENSE-2.0
- *
- * This file is part of the Apache Pekko project, which was derived from Akka.
- */
-
-/*
- * Copyright (C) 2018-2022 Lightbend Inc. <https://www.lightbend.com>
- */
-
-/*
- * Scala (https://www.scala-lang.org)
- *
- * Copyright EPFL and Lightbend, Inc.
- *
- * Licensed under Apache License 2.0
- * (http://www.apache.org/licenses/LICENSE-2.0).
- *
- * See the NOTICE file distributed with this work for
- * additional information regarding copyright ownership.
- */
-
-package org.apache.pekko.http
-
-import org.apache.pekko
-import scala.collection.generic.{ CanBuildFrom, GenericCompanion }
-import scala.collection.{ mutable, GenTraversable }
-import scala.{ collection => c }
-
-/**
- * INTERNAL API
- *
- * Partly based on https://github.com/scala/scala-collection-compat/blob/main/compat/src/main/scala-2.11_2.12/scala/collection/compat/PackageShared.scala
- * but reproduced here so we don't need to add a dependency on this library. It contains much more than we need right now, and is
- * not promising binary compatibility yet at the time of writing.
- */
-package object ccompat {
-  import CompatImpl._
-
-  implicit def genericCompanionToCBF[A, CC[X] <: GenTraversable[X]](
-      fact: GenericCompanion[CC]): CanBuildFrom[Any, A, CC[A]] =
-    simpleCBF(fact.newBuilder[A])
-
-  // This really belongs into scala.collection but there's already a package object
-  // in scala-library so we can't add to it
-  type IterableOnce[+X] = c.TraversableOnce[X]
-  val IterableOnce = c.TraversableOnce
-
-  implicit class RichQueue[T](val queue: mutable.Queue[T]) extends AnyVal {
-    // missing in 2.12
-    def -=(element: T): Unit = queue.dequeueAll(_ == element)
-  }
-}
-
-/**
- * INTERNAL API
- */
-package ccompat {
-  trait Builder[-Elem, +To] extends mutable.Builder[Elem, To] { self =>
-    // This became final in 2.13 so cannot be overridden there anymore
-    final override def +=(elem: Elem): this.type = addOne(elem)
-    def addOne(elem: Elem): this.type = self.+=(elem)
-  }
-
-  trait QuerySeqOptimized extends scala.collection.immutable.LinearSeq[(String, String)]
-      with scala.collection.LinearSeqOptimized[(String, String), pekko.http.scaladsl.model.Uri.Query] {
-    self: pekko.http.scaladsl.model.Uri.Query =>
-    override def newBuilder: mutable.Builder[(String, String), pekko.http.scaladsl.model.Uri.Query] =
-      pekko.http.scaladsl.model.Uri.Query.newBuilder
-  }
-}
diff --git a/http-core/src/main/scala-2.13-/org/apache/pekko/http/scaladsl/util/FastFuture.scala b/http-core/src/main/scala-2.13-/org/apache/pekko/http/scaladsl/util/FastFuture.scala
deleted file mode 100644
index e773fb683..000000000
--- a/http-core/src/main/scala-2.13-/org/apache/pekko/http/scaladsl/util/FastFuture.scala
+++ /dev/null
@@ -1,139 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * license agreements; and to You under the Apache License, version 2.0:
- *
- *   https://www.apache.org/licenses/LICENSE-2.0
- *
- * This file is part of the Apache Pekko project, which was derived from Akka.
- */
-
-/*
- * Copyright (C) 2009-2022 Lightbend Inc. <https://www.lightbend.com>
- */
-
-package org.apache.pekko.http.scaladsl.util
-
-import scala.language.higherKinds
-import scala.util.control.NonFatal
-import scala.util.{ Failure, Success, Try }
-import scala.collection.generic.CanBuildFrom
-import scala.concurrent.duration.Duration
-import scala.concurrent._
-
-/**
- * Provides alternative implementations of the basic transformation operations defined on [[scala.concurrent.Future]],
- * which try to avoid scheduling to an [[scala.concurrent.ExecutionContext]] if possible, i.e. if the given future
- * value is already present.
- */
-class FastFuture[A](val future: Future[A]) extends AnyVal {
-  import FastFuture._
-
-  def map[B](f: A => B)(implicit ec: ExecutionContext): Future[B] =
-    transformWith(a => FastFuture.successful(f(a)), FastFuture.failed)
-
-  def flatMap[B](f: A => Future[B])(implicit ec: ExecutionContext): Future[B] =
-    transformWith(f, FastFuture.failed)
-
-  def filter(pred: A => Boolean)(implicit executor: ExecutionContext): Future[A] =
-    flatMap { r =>
-      if (pred(r)) future
-      else throw new NoSuchElementException("Future.filter predicate is not satisfied")
-    }
-
-  def foreach(f: A => Unit)(implicit ec: ExecutionContext): Unit = map(f)
-
-  def transformWith[B](f: Try[A] => Future[B])(implicit executor: ExecutionContext): Future[B] =
-    transformWith(a => f(Success(a)), e => f(Failure(e)))
-
-  def transformWith[B](s: A => Future[B], f: Throwable => Future[B])(implicit executor: ExecutionContext): Future[B] = {
-    def strictTransform[T](x: T, f: T => Future[B]) =
-      try f(x)
-      catch { case NonFatal(e) => ErrorFuture(e) }
-
-    future match {
-      case FulfilledFuture(a) => strictTransform(a, s)
-      case ErrorFuture(e)     => strictTransform(e, f)
-      case _ => future.value match {
-          case None =>
-            val p = Promise[B]()
-            future.onComplete {
-              case Success(a) => p.completeWith(strictTransform(a, s))
-              case Failure(e) => p.completeWith(strictTransform(e, f))
-            }
-            p.future
-          case Some(Success(a)) => strictTransform(a, s)
-          case Some(Failure(e)) => strictTransform(e, f)
-        }
-    }
-  }
-
-  def recover[B >: A](pf: PartialFunction[Throwable, B])(implicit ec: ExecutionContext): Future[B] =
-    transformWith(FastFuture.successful, t => if (pf.isDefinedAt(t)) FastFuture.successful(pf(t)) else future)
-
-  def recoverWith[B >: A](pf: PartialFunction[Throwable, Future[B]])(implicit ec: ExecutionContext): Future[B] =
-    transformWith(FastFuture.successful, t => pf.applyOrElse(t, (_: Throwable) => future))
-}
-
-object FastFuture {
-  def apply[T](value: Try[T]): Future[T] = value match {
-    case Success(t) => FulfilledFuture(t)
-    case Failure(e) => ErrorFuture(e)
-  }
-  private[this] val _successful: Any => Future[Any] = FulfilledFuture.apply
-  def successful[T]: T => Future[T] = _successful.asInstanceOf[T => Future[T]]
-  val failed: Throwable => Future[Nothing] = ErrorFuture.apply
-
-  private case class FulfilledFuture[+A](a: A) extends Future[A] {
-    def value = Some(Success(a))
-    def onComplete[U](f: Try[A] => U)(implicit executor: ExecutionContext) = Future.successful(a).onComplete(f)
-    def isCompleted = true
-    def result(atMost: Duration)(implicit permit: CanAwait) = a
-    def ready(atMost: Duration)(implicit permit: CanAwait) = this
-    def transform[S](f: scala.util.Try[A] => scala.util.Try[S])(
-        implicit executor: scala.concurrent.ExecutionContext): scala.concurrent.Future[S] =
-      FastFuture(f(Success(a)))
-    def transformWith[S](f: scala.util.Try[A] => scala.concurrent.Future[S])(
-        implicit executor: scala.concurrent.ExecutionContext): scala.concurrent.Future[S] =
-      new FastFuture(this).transformWith(f)
-  }
-  private case class ErrorFuture(error: Throwable) extends Future[Nothing] {
-    def value = Some(Failure(error))
-    def onComplete[U](f: Try[Nothing] => U)(implicit executor: ExecutionContext) = Future.failed(error).onComplete(f)
-    def isCompleted = true
-    def result(atMost: Duration)(implicit permit: CanAwait) = throw error
-    def ready(atMost: Duration)(implicit permit: CanAwait) = this
-    def transform[S](f: scala.util.Try[Nothing] => scala.util.Try[S])(
-        implicit executor: scala.concurrent.ExecutionContext): scala.concurrent.Future[S] =
-      FastFuture(f(Failure(error)))
-    def transformWith[S](f: scala.util.Try[Nothing] => scala.concurrent.Future[S])(
-        implicit executor: scala.concurrent.ExecutionContext): scala.concurrent.Future[S] =
-      new FastFuture(this).transformWith(f)
-  }
-
-  implicit class EnhancedFuture[T](val future: Future[T]) extends AnyVal {
-    def fast: FastFuture[T] = new FastFuture[T](future)
-  }
-
-  def sequence[T, M[_] <: TraversableOnce[_]](in: M[Future[T]])(implicit cbf: CanBuildFrom[M[Future[T]], T, M[T]],
-      executor: ExecutionContext): Future[M[T]] =
-    in.foldLeft(successful(cbf(in))) {
-      (fr, fa) => for (r <- fr.fast; a <- fa.asInstanceOf[Future[T]].fast) yield r += a
-    }.fast.map(_.result())
-
-  def fold[T, R](futures: TraversableOnce[Future[T]])(zero: R)(f: (R, T) => R)(
-      implicit executor: ExecutionContext): Future[R] =
-    if (futures.isEmpty) successful(zero)
-    else sequence(futures).fast.map(_.foldLeft(zero)(f))
-
-  def reduce[T, R >: T](futures: TraversableOnce[Future[T]])(op: (R, T) => R)(
-      implicit executor: ExecutionContext): Future[R] =
-    if (futures.isEmpty) failed(new NoSuchElementException("reduce attempted on empty collection"))
-    else sequence(futures).fast.map(_.reduceLeft(op))
-
-  def traverse[A, B, M[_] <: TraversableOnce[_]](in: M[A])(fn: A => Future[B])(
-      implicit cbf: CanBuildFrom[M[A], B, M[B]], executor: ExecutionContext): Future[M[B]] =
-    in.foldLeft(successful(cbf(in))) { (fr, a) =>
-      val fb = fn(a.asInstanceOf[A])
-      for (r <- fr.fast; b <- fb.fast) yield r += b
-    }.fast.map(_.result())
-}
diff --git a/http-core/src/main/scala-2.13+/org/apache/pekko/http/ccompat/MapHelpers.scala b/http-core/src/main/scala/org/apache/pekko/http/ccompat/MapHelpers.scala
similarity index 100%
rename from http-core/src/main/scala-2.13+/org/apache/pekko/http/ccompat/MapHelpers.scala
rename to http-core/src/main/scala/org/apache/pekko/http/ccompat/MapHelpers.scala
diff --git a/http-core/src/main/scala-2.13+/org/apache/pekko/http/ccompat/imm/package.scala b/http-core/src/main/scala/org/apache/pekko/http/ccompat/imm/package.scala
similarity index 100%
rename from http-core/src/main/scala-2.13+/org/apache/pekko/http/ccompat/imm/package.scala
rename to http-core/src/main/scala/org/apache/pekko/http/ccompat/imm/package.scala
diff --git a/http-core/src/main/scala-2.13+/org/apache/pekko/http/ccompat/package.scala b/http-core/src/main/scala/org/apache/pekko/http/ccompat/package.scala
similarity index 100%
rename from http-core/src/main/scala-2.13+/org/apache/pekko/http/ccompat/package.scala
rename to http-core/src/main/scala/org/apache/pekko/http/ccompat/package.scala
diff --git a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/HttpMessage.scala b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/HttpMessage.scala
index 43b307b3e..447aa2a15 100644
--- a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/HttpMessage.scala
+++ b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/HttpMessage.scala
@@ -30,7 +30,7 @@ import pekko.Done
 import pekko.actor.ClassicActorSystemProvider
 import org.parboiled2.CharUtils
 import pekko.util.{ ByteString, HashCode, OptionVal }
-import pekko.http.ccompat.{ pre213, since213 }
+import pekko.http.ccompat.since213
 import pekko.http.impl.util._
 import pekko.http.javadsl.{ model => jm }
 import pekko.http.scaladsl.util.FastFuture._
@@ -82,7 +82,6 @@ sealed trait HttpMessage extends jm.HttpMessage {
     entity.discardBytes()(SystemMaterializer(system).materializer)
 
   /** Returns a copy of this message with the list of headers set to the given ones. */
-  @pre213
   def withHeaders(headers: HttpHeader*): Self = withHeaders(headers.toList)
 
   /** Returns a copy of this message with the list of headers set to the given ones. */
@@ -97,7 +96,6 @@ sealed trait HttpMessage extends jm.HttpMessage {
    * Returns a new message that contains all of the given default headers which didn't already
    * exist (by case-insensitive header name) in this message.
    */
-  @pre213
   def withDefaultHeaders(defaultHeaders: HttpHeader*): Self = withDefaultHeaders(defaultHeaders.toList)
 
   @since213
diff --git a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/CacheDirective.scala b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/CacheDirective.scala
index 3152c8c07..08b76230f 100644
--- a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/CacheDirective.scala
+++ b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/CacheDirective.scala
@@ -20,7 +20,7 @@ import scala.annotation.{ tailrec, varargs }
 import scala.collection.immutable
 import pekko.http.impl.util._
 import pekko.http.javadsl.{ model => jm }
-import pekko.http.ccompat.{ pre213, since213 }
+import pekko.http.ccompat.since213
 
 sealed trait CacheDirective extends Renderable with jm.headers.CacheDirective {
   def value: String
@@ -93,7 +93,6 @@ object CacheDirectives {
    * http://tools.ietf.org/html/rfc7234#section-5.2.1.4
    */
   case object `no-cache` extends SingletonValueRenderable with RequestDirective with ResponseDirective {
-    @pre213
     def apply(fieldNames: String*): `no-cache` =
       new `no-cache`(immutable.Seq(fieldNames: _*))
     @since213
@@ -148,7 +147,6 @@ object CacheDirectives {
    */
   final case class `private`(fieldNames: immutable.Seq[String]) extends FieldNamesDirective with ResponseDirective
   object `private` {
-    @pre213
     def apply(fieldNames: String*): `private` = new `private`(immutable.Seq(fieldNames: _*))
     @since213
     def apply(): `private` = new `private`(immutable.Seq.empty)
diff --git a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/LanguageRange.scala b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/LanguageRange.scala
index 56bdfbfe9..94eb9d3f5 100644
--- a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/LanguageRange.scala
+++ b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/LanguageRange.scala
@@ -20,7 +20,7 @@ import pekko.http.impl.util._
 import pekko.http.scaladsl.model.WithQValue
 import pekko.http.javadsl.{ model => jm }
 import pekko.http.impl.util.JavaMapping.Implicits._
-import pekko.http.ccompat.{ pre213, since213 }
+import pekko.http.ccompat.since213
 
 sealed trait LanguageRange extends jm.headers.LanguageRange with ValueRenderable with WithQValue[LanguageRange] {
   def qValue: Float
@@ -82,7 +82,6 @@ object Language {
       val tags = compoundTag.split('-')
       new Language(tags.head, immutable.Seq(tags.tail: _*))
     } else new Language(compoundTag, immutable.Seq.empty)
-  @pre213
   def apply(primaryTag: String, subTags: String*): Language =
     new Language(primaryTag, immutable.Seq(subTags: _*))
   @since213
diff --git a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/LinkValue.scala b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/LinkValue.scala
index 449be0cc8..abecb0d7b 100644
--- a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/LinkValue.scala
+++ b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/LinkValue.scala
@@ -21,7 +21,7 @@ import pekko.http.scaladsl.model._
 import pekko.http.javadsl.{ model => jm }
 import pekko.http.impl.util.JavaMapping.Implicits._
 import UriRendering.UriRenderer
-import pekko.http.ccompat.{ pre213, since213 }
+import pekko.http.ccompat.since213
 
 final case class LinkValue(uri: Uri, params: immutable.Seq[LinkParam]) extends jm.headers.LinkValue
     with ValueRenderable {
@@ -36,7 +36,6 @@ final case class LinkValue(uri: Uri, params: immutable.Seq[LinkParam]) extends j
 }
 
 object LinkValue {
-  @pre213
   def apply(uri: Uri, params: LinkParam*): LinkValue = apply(uri, immutable.Seq(params: _*))
   @since213
   def apply(uri: Uri, firstParam: LinkParam, otherParams: LinkParam*): LinkValue = apply(uri, firstParam +: otherParams)
diff --git a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/headers.scala b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/headers.scala
index 5f639e39e..d51ed3fb5 100644
--- a/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/headers.scala
+++ b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/model/headers/headers.scala
@@ -29,7 +29,7 @@ import scala.annotation.tailrec
 import scala.collection.immutable
 import org.parboiled2.util.Base64
 import pekko.event.Logging
-import pekko.http.ccompat.{ pre213, since213 }
+import pekko.http.ccompat.since213
 import pekko.http.impl.util._
 import pekko.http.impl.model.parser.CharacterClasses.`attr-char`
 import pekko.http.javadsl.{ model => jm }
@@ -147,7 +147,6 @@ import pekko.http.impl.util.JavaMapping.Implicits._
 
 // https://tools.ietf.org/html/rfc7231#section-5.3.2
 object Accept extends ModeledCompanion[Accept] {
-  @pre213
   def apply(mediaRanges: MediaRange*): Accept =
     apply(immutable.Seq(mediaRanges: _*))
   @since213
@@ -185,7 +184,6 @@ final case class `Accept-Charset`(charsetRanges: immutable.Seq[HttpCharsetRange]
 
 // https://tools.ietf.org/html/rfc7231#section-5.3.4
 object `Accept-Encoding` extends ModeledCompanion[`Accept-Encoding`] {
-  @pre213
   def apply(encodings: HttpEncodingRange*): `Accept-Encoding` =
     apply(immutable.Seq(encodings: _*))
   @since213
@@ -226,7 +224,6 @@ final case class `Accept-Language`(languages: immutable.Seq[LanguageRange]) exte
 
 // https://tools.ietf.org/html/rfc7233#section-2.3
 object `Accept-Ranges` extends ModeledCompanion[`Accept-Ranges`] {
-  @pre213
   def apply(rangeUnits: RangeUnit*): `Accept-Ranges` =
     apply(immutable.Seq(rangeUnits: _*))
   @since213
@@ -257,7 +254,6 @@ final case class `Access-Control-Allow-Credentials`(allow: Boolean)
 
 // https://www.w3.org/TR/cors/#access-control-allow-headers-response-header
 object `Access-Control-Allow-Headers` extends ModeledCompanion[`Access-Control-Allow-Headers`] {
-  @pre213
   def apply(headers: String*): `Access-Control-Allow-Headers` =
     apply(immutable.Seq(headers: _*))
   @since213
@@ -277,7 +273,6 @@ final case class `Access-Control-Allow-Headers`(headers: immutable.Seq[String])
 
 // https://www.w3.org/TR/cors/#access-control-allow-methods-response-header
 object `Access-Control-Allow-Methods` extends ModeledCompanion[`Access-Control-Allow-Methods`] {
-  @pre213
   def apply(methods: HttpMethod*): `Access-Control-Allow-Methods` =
     apply(immutable.Seq(methods: _*))
   @since213
@@ -318,7 +313,6 @@ final case class `Access-Control-Allow-Origin` private (range: HttpOriginRange)
 
 // https://www.w3.org/TR/cors/#access-control-expose-headers-response-header
 object `Access-Control-Expose-Headers` extends ModeledCompanion[`Access-Control-Expose-Headers`] {
-  @pre213
   def apply(headers: String*): `Access-Control-Expose-Headers` =
     apply(immutable.Seq(headers: _*))
   @since213
@@ -346,7 +340,6 @@ final case class `Access-Control-Max-Age`(deltaSeconds: Long) extends jm.headers
 
 // https://www.w3.org/TR/cors/#access-control-request-headers-request-header
 object `Access-Control-Request-Headers` extends ModeledCompanion[`Access-Control-Request-Headers`] {
-  @pre213
   def apply(headers: String*): `Access-Control-Request-Headers` =
     apply(immutable.Seq(headers: _*))
   @since213
@@ -381,7 +374,6 @@ final case class Age(deltaSeconds: Long) extends jm.headers.Age with ResponseHea
 
 // https://tools.ietf.org/html/rfc7231#section-7.4.1
 object Allow extends ModeledCompanion[Allow] {
-  @pre213
   def apply(methods: HttpMethod*): Allow =
     apply(immutable.Seq(methods: _*))
   @since213
@@ -564,7 +556,6 @@ final case class `Content-Type` private[pekko] (contentType: ContentType) extend
 object Cookie extends ModeledCompanion[Cookie] {
   def apply(first: HttpCookiePair, more: HttpCookiePair*): Cookie = apply(immutable.Seq(first +: more: _*))
   def apply(name: String, value: String): Cookie = apply(HttpCookiePair(name, value))
-  @pre213
   def apply(values: (String, String)*): Cookie = apply(values.map(HttpCookiePair(_)).toList)
   @since213
   def apply(first: (String, String), more: (String, String)*): Cookie = apply((first +: more).map(HttpCookiePair(_)))
@@ -716,7 +707,6 @@ final case class `Last-Modified`(date: DateTime) extends jm.headers.LastModified
 object Link extends ModeledCompanion[Link] {
   def apply(uri: Uri, first: LinkParam, more: LinkParam*): Link =
     apply(immutable.Seq(LinkValue(uri, first +: more.toList)))
-  @pre213
   def apply(values: LinkValue*): Link = apply(immutable.Seq(values: _*))
   @since213
   def apply(firstValue: LinkValue, otherValues: LinkValue*): Link = apply(firstValue +: otherValues)
@@ -744,7 +734,6 @@ final case class Location(uri: Uri) extends jm.headers.Location with ResponseHea
 
 // https://tools.ietf.org/html/rfc6454#section-7
 object Origin extends ModeledCompanion[Origin] {
-  @pre213
   def apply(origins: HttpOrigin*): Origin = apply(immutable.Seq(origins: _*))
   @since213
   def apply(firstOrigin: HttpOrigin, otherOrigins: HttpOrigin*): Origin = apply(firstOrigin +: otherOrigins)
diff --git a/http-core/src/main/scala-2.13+/org/apache/pekko/http/scaladsl/util/FastFuture.scala b/http-core/src/main/scala/org/apache/pekko/http/scaladsl/util/FastFuture.scala
similarity index 100%
rename from http-core/src/main/scala-2.13+/org/apache/pekko/http/scaladsl/util/FastFuture.scala
rename to http-core/src/main/scala/org/apache/pekko/http/scaladsl/util/FastFuture.scala
diff --git a/http-core/src/test/scala/io/pekko/integrationtest/http/HttpModelIntegrationSpec.scala b/http-core/src/test/scala/io/pekko/integrationtest/http/HttpModelIntegrationSpec.scala
index 9cf55f763..56fb64529 100644
--- a/http-core/src/test/scala/io/pekko/integrationtest/http/HttpModelIntegrationSpec.scala
+++ b/http-core/src/test/scala/io/pekko/integrationtest/http/HttpModelIntegrationSpec.scala
@@ -21,7 +21,6 @@ import org.scalatest.BeforeAndAfterAll
 import org.apache.pekko
 import pekko.util.ByteString
 import pekko.actor.ActorSystem
-import pekko.http.ccompat._ // required for Scala 2.12 compilation
 import pekko.http.scaladsl.model._
 import pekko.stream.scaladsl._
 import pekko.testkit._
diff --git a/http-scalafix/README.md b/http-scalafix/README.md
index 3bc3bc429..035254586 100644
--- a/http-scalafix/README.md
+++ b/http-scalafix/README.md
@@ -11,6 +11,3 @@ The setup of the scalafix module roughly follows the example in https://github.c
  * run `scalafixEnable` on the sbt shell (this will unfortunately require a complete rebuild afterwards)
  * run `set scalacOptions in ThisBuild += "-P:semanticdb:synthetics:on"` to allow access to synthetics
  * e.g. run `docs/scalafixAll MigrateToServerBuilder`
-
-*Note:* There's some weird stuff going on regarding cross-publishing. If running the rule fails with a weird error, try switching to Scala 2.12 first with `++2.12.11` (or
-whatever is now the current version).
diff --git a/http-tests/src/test/scala-2.13-/main/org/apache/pekko/http/scaladsl/server/util/package.scala b/http-tests/src/test/scala-2.13-/main/org/apache/pekko/http/scaladsl/server/util/package.scala
deleted file mode 100644
index a19bed487..000000000
--- a/http-tests/src/test/scala-2.13-/main/org/apache/pekko/http/scaladsl/server/util/package.scala
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * license agreements; and to You under the Apache License, version 2.0:
- *
- *   https://www.apache.org/licenses/LICENSE-2.0
- *
- * This file is part of the Apache Pekko project, which was derived from Akka.
- */
-
-/*
- * Copyright (C) 2009-2022 Lightbend Inc. <https://www.lightbend.com>
- */
-
-package org.apache.pekko.http.scaladsl.server
-
-package object util {
-  type VarArgsFunction1[-T, +U] = (T*) => U
-}
diff --git a/http-tests/src/test/scala-2.13-/src/main/org/apache/pekko/http/ccompat/ImplicitUtils.scala b/http-tests/src/test/scala-2.13-/src/main/org/apache/pekko/http/ccompat/ImplicitUtils.scala
deleted file mode 100644
index 2ceafb7f8..000000000
--- a/http-tests/src/test/scala-2.13-/src/main/org/apache/pekko/http/ccompat/ImplicitUtils.scala
+++ /dev/null
@@ -1,16 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * license agreements; and to You under the Apache License, version 2.0:
- *
- *   https://www.apache.org/licenses/LICENSE-2.0
- *
- * This file is part of the Apache Pekko project, which was derived from Akka.
- */
-
-/*
- * Copyright (C) 2009-2022 Lightbend Inc. <https://www.lightbend.com>
- */
-
-package org.apache.pekko.http.ccompat
-
-object ImplicitUtils
diff --git a/http-tests/src/test/scala-2.13+/org/apache/pekko/http/scaladsl/server/util/VarArgsFunction1.scala b/http-tests/src/test/scala/org/apache/pekko/http/scaladsl/server/util/VarArgsFunction1.scala
similarity index 100%
rename from http-tests/src/test/scala-2.13+/org/apache/pekko/http/scaladsl/server/util/VarArgsFunction1.scala
rename to http-tests/src/test/scala/org/apache/pekko/http/scaladsl/server/util/VarArgsFunction1.scala
diff --git a/http/src/main/scala/org/apache/pekko/http/scaladsl/server/directives/FormFieldDirectives.scala b/http/src/main/scala/org/apache/pekko/http/scaladsl/server/directives/FormFieldDirectives.scala
index aa5977869..d4873255c 100644
--- a/http/src/main/scala/org/apache/pekko/http/scaladsl/server/directives/FormFieldDirectives.scala
+++ b/http/src/main/scala/org/apache/pekko/http/scaladsl/server/directives/FormFieldDirectives.scala
@@ -27,7 +27,6 @@ import scala.collection.immutable
 import scala.concurrent.Future
 import scala.util.{ Failure, Success }
 import BasicDirectives._
-import pekko.http.ccompat.pre213
 import pekko.http.ccompat.since213
 
 /**
diff --git a/http/src/main/scala/org/apache/pekko/http/scaladsl/server/directives/RespondWithDirectives.scala b/http/src/main/scala/org/apache/pekko/http/scaladsl/server/directives/RespondWithDirectives.scala
index 97fe3ffd8..beed18cd4 100644
--- a/http/src/main/scala/org/apache/pekko/http/scaladsl/server/directives/RespondWithDirectives.scala
+++ b/http/src/main/scala/org/apache/pekko/http/scaladsl/server/directives/RespondWithDirectives.scala
@@ -47,7 +47,6 @@ trait RespondWithDirectives {
    *
    * @group response
    */
-  @pre213
   def respondWithHeaders(responseHeaders: HttpHeader*): Directive0 =
     respondWithHeaders(responseHeaders.toList)
 
@@ -69,7 +68,6 @@ trait RespondWithDirectives {
    *
    * @group response
    */
-  @pre213
   def respondWithDefaultHeaders(responseHeaders: HttpHeader*): Directive0 =
     respondWithDefaultHeaders(responseHeaders.toList)
 
diff --git a/parsing/src/main/scala-2/org/apache/pekko/http/ccompat/pre213macro.scala b/parsing/src/main/scala-2/org/apache/pekko/http/ccompat/pre213macro.scala
deleted file mode 100644
index 1edf051ef..000000000
--- a/parsing/src/main/scala-2/org/apache/pekko/http/ccompat/pre213macro.scala
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * license agreements; and to You under the Apache License, version 2.0:
- *
- *   https://www.apache.org/licenses/LICENSE-2.0
- *
- * This file is part of the Apache Pekko project, which was derived from Akka.
- */
-
-/*
- * Copyright (C) 2019-2022 Lightbend Inc. <https://www.lightbend.com>
- */
-
-package org.apache.pekko.http.ccompat
-
-import scala.annotation.StaticAnnotation
-import scala.language.experimental.macros
-import scala.reflect.macros.blackbox.Context
-
-object pre213macro {
-  def impl(c: Context)(annottees: c.Expr[Any]*): c.Expr[Any] = annottees match {
-    case Seq(method) =>
-      import c.universe._
-      if (scala.util.Properties.versionNumberString.startsWith("2.13"))
-        c.Expr[Nothing](EmptyTree)
-      else
-        method
-    case _ =>
-      c.abort(c.enclosingPosition, "Please annotate single expressions")
-  }
-}
-class pre213 extends StaticAnnotation {
-  def macroTransform(annottees: Any*): Any = macro pre213macro.impl
-}
diff --git a/parsing/src/main/scala-3/org/apache/pekko/http/ccompat/pre213macro.scala b/parsing/src/main/scala-3/org/apache/pekko/http/ccompat/pre213macro.scala
deleted file mode 100644
index 21dd8a0c2..000000000
--- a/parsing/src/main/scala-3/org/apache/pekko/http/ccompat/pre213macro.scala
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * license agreements; and to You under the Apache License, version 2.0:
- *
- *   https://www.apache.org/licenses/LICENSE-2.0
- *
- * This file is part of the Apache Pekko project, which was derived from Akka.
- */
-
-/*
- * Copyright (C) 2019-2022 Lightbend Inc. <https://www.lightbend.com>
- */
-
-package org.apache.pekko.http.ccompat
-
-import scala.annotation.StaticAnnotation
-
-// FIXME: need to implement or we will resurrect some ugly things (or remove 2.12 support)
-class pre213 extends StaticAnnotation
diff --git a/project/Common.scala b/project/Common.scala
index da0762a30..0b76bf1e0 100644
--- a/project/Common.scala
+++ b/project/Common.scala
@@ -48,9 +48,6 @@ object Common extends AutoPlugin {
     Global / parallelExecution := sys.props.getOrElse("pekko.http.parallelExecution", "true") != "false")
 
   val javacTarget: String = "17"
-  def onlyAfterScala212[T](values: Seq[T]): Def.Initialize[Seq[T]] = Def.setting {
-    if (scalaMinorVersion.value >= 12) values else Seq.empty[T]
-  }
   def onlyOnScala2[T](values: Seq[T]): Def.Initialize[Seq[T]] = Def.setting {
     if (scalaVersion.value.startsWith("3")) Seq.empty[T] else values
   }
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 0d627d346..d3d64a3c2 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -33,10 +33,9 @@ object Dependencies {
 
   val scalafixVersion = _root_.scalafix.sbt.BuildInfo.scalafixVersion // grab from plugin
 
-  val scala212Version = "2.12.20"
   val scala213Version = "2.13.16"
   val scala3Version = "3.3.6"
-  val allScalaVersions = Seq(scala213Version, scala212Version, scala3Version)
+  val allScalaVersions = Seq(scala213Version, scala3Version)
 
   val Versions = Seq(
     crossScalaVersions := allScalaVersions,
diff --git a/project/Pre213Preprocessor.scala b/project/Pre213Preprocessor.scala
deleted file mode 100644
index 79a91c77a..000000000
--- a/project/Pre213Preprocessor.scala
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * license agreements; and to You under the Apache License, version 2.0:
- *
- *   https://www.apache.org/licenses/LICENSE-2.0
- *
- * This file is part of the Apache Pekko project, which was derived from Akka.
- */
-
-import sbt._
-import Keys._
-
-object Pre213Preprocessor extends AutoPlugin {
-  val pre213Files = settingKey[Seq[String]]("files that should be edited for pre213 annotation")
-
-  val pattern = """(?s)@pre213.*?@since213""".r
-
-  override def projectSettings: Seq[Def.Setting[_]] = {
-    Compile / sources := {
-      if (scalaVersion.value.startsWith("3")) {
-        val filter: File => Boolean =
-          f => pre213Files.value.exists(suffix => f.getAbsolutePath.replace("\\", "//").endsWith(suffix))
-        (Compile / sources).value.map { s =>
-          if (filter(s)) {
-            val data = IO.read(s)
-            val targetFile = sourceManaged.value / s.getName
-            val newData = pattern.replaceAllIn(data, "@since213")
-            IO.write(targetFile, newData)
-            targetFile
-          } else s
-        }
-      } else (Compile / sources).value
-    }
-  }
-}