diff --git a/build.sbt b/build.sbt
index 63c5e1c222..3774c973b2 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,4 +1,4 @@
-import akka.{AutomaticModuleName, CopyrightHeaderForBuild, Paradox, ParadoxSupport, ScalafixIgnoreFilePlugin}
+import akka.{AutomaticModuleName, CopyrightHeaderForBuild, Paradox, ScalafixIgnoreFilePlugin}
 
 enablePlugins(
   UnidocRoot,
@@ -205,7 +205,6 @@ lazy val docs = akkaModule("akka-docs")
     persistenceTestkit % "compile->compile;test->test")
   .settings(Dependencies.docs)
   .settings(Paradox.settings)
-  .settings(ParadoxSupport.paradoxWithCustomDirectives)
   .settings(javacOptions += "-parameters") // for Jackson
   .enablePlugins(
     AkkaParadoxPlugin,
diff --git a/project/ParadoxSupport.scala b/project/ParadoxSupport.scala
deleted file mode 100644
index 4d8289534c..0000000000
--- a/project/ParadoxSupport.scala
+++ /dev/null
@@ -1,94 +0,0 @@
-/*
- * Copyright (C) 2016-2020 Lightbend Inc. <https://www.lightbend.com>
- */
-
-package akka
-
-import java.io.{File, FileNotFoundException}
-
-import com.lightbend.paradox.markdown._
-import com.lightbend.paradox.sbt.ParadoxPlugin.autoImport._
-import org.pegdown.Printer
-import org.pegdown.ast._
-import sbt.Keys._
-import sbt._
-
-import scala.annotation.tailrec
-import scala.io.{Codec, Source}
-import scala.collection.JavaConverters._
-
-object ParadoxSupport {
-  val paradoxWithCustomDirectives = Seq(
-    paradoxDirectives ++= Def.taskDyn {
-      val log = streams.value.log
-      val classpath = (fullClasspath in Compile).value.files.map(_.toURI.toURL).toArray
-      val classloader = new java.net.URLClassLoader(classpath, this.getClass().getClassLoader())
-      import _root_.io.github.classgraph.ClassGraph
-      lazy val scanner = new ClassGraph()
-        .whitelistPackages("akka")
-        .addClassLoader(classloader)
-        .scan()
-      val allClasses = scanner.getAllClasses.getNames.asScala.toVector
-      Def.task { Seq(
-        { context: Writer.Context =>
-                    new SignatureDirective(context.location.tree.label, context.properties, context)
-        },
-      )}
-    }.value
-  )
-
-  class SignatureDirective(page: Page, variables: Map[String, String], ctx: Writer.Context) extends LeafBlockDirective("signature") {
-    def render(node: DirectiveNode, visitor: Visitor, printer: Printer): Unit =
-      try {
-        val labels = node.attributes.values("identifier").asScala.map(_.toLowerCase())
-        val source = node.source match {
-          case direct: DirectiveNode.Source.Direct => direct.value
-          case _                                   => sys.error("Source references are not supported")
-        }
-        val file =
-          if (source startsWith "/") {
-            // snip.build.base_dir defined by Paradox
-            val base = new File(PropertyUrl("snip.build.base_dir", variables.get).base.trim)
-            new File(base, source)
-          } else new File(page.file.getParentFile, source)
-
-        val Signature = """\s*((def|val|type) (\w+)(?=[:(\[]).*)(\s+\=.*)""".r // stupid approximation to match a signature
-
-        val text =
-          getDefs(file).collect {
-            case line@Signature(signature, kind, l, definition) if labels contains l.replaceAll("Mat$", "").toLowerCase() =>
-              //println(s"Found label '$l' with sig '$full' in line $line")
-              if (kind == "type") signature + definition
-              else signature
-          }.mkString("\n")
-
-        if (text.trim.isEmpty) {
-          throw new IllegalArgumentException(
-            s"Did not find any signatures with one of those names [${labels.mkString(", ")}] in $source " +
-            s"(was referenced from [${page.path}])")
-        } else {
-          val lang = Option(node.attributes.value("type")).getOrElse(Snippet.language(file))
-          new VerbatimNode(text, lang).accept(visitor)
-        }
-      } catch {
-        case e: FileNotFoundException =>
-          ctx.error(s"Unknown snippet [${e.getMessage}]", node)
-      }
-  }
-
-  def getDefs(file: File): Seq[String] = {
-    val Indented = "(\\s*)(.*)".r
-
-    @tailrec
-    def rec(lines: Iterator[String], currentDef: Option[String], defIndent: Integer, soFar: Seq[String]): Seq[String] = {
-      if (!lines.hasNext) soFar ++ currentDef
-      else lines.next() match {
-        case Indented(indent, line) =>
-          if (line.startsWith("def")) rec(lines, Some(line), indent.length, soFar ++ currentDef)
-          else if (indent.length == defIndent + 4) rec(lines, currentDef.map(_ ++ line), defIndent, soFar)
-          else rec(lines, None, 0, soFar ++ currentDef)
-      }
-    }
-    rec(Source.fromFile(file)(Codec.UTF8).getLines, None, 0, Nil)
-  }
-}