diff --git a/project/JavaFormatter.scala b/project/JavaFormatter.scala
index c7293f3db9..7fd8ba441f 100644
--- a/project/JavaFormatter.scala
+++ b/project/JavaFormatter.scala
@@ -6,15 +6,14 @@ import akka.ProjectFileIgnoreSupport
 import com.lightbend.sbt.JavaFormatterPlugin
 import sbt.{AutoPlugin, PluginTrigger, Plugins}
 
-object JavaFormatter extends AutoPlugin with ProjectFileIgnoreSupport {
+object JavaFormatter extends AutoPlugin {
 
   override def trigger = PluginTrigger.AllRequirements
 
   override def requires: Plugins = JavaFormatterPlugin
 
-  final override protected val ignoreConfigFileName: String = ".sbt-java-formatter.conf"
-
-  final override protected val descriptor: String = "sbt-java-formatter"
+  private val ignoreConfigFileName: String = ".sbt-java-formatter.conf"
+  private val descriptor: String = "sbt-java-formatter"
 
   import JavaFormatterPlugin.autoImport._
   import sbt.Keys._
@@ -24,7 +23,8 @@ object JavaFormatter extends AutoPlugin with ProjectFileIgnoreSupport {
   override def projectSettings: Seq[Def.Setting[_]] = Seq(
     //below is for sbt java formatter
     (excludeFilter in format) := {
-      val simpleFileFilter = new SimpleFileFilter(file => isIgnoredByFileOrPackages(file))
+      val ignoreSupport = new ProjectFileIgnoreSupport((baseDirectory in ThisBuild).value / ignoreConfigFileName, descriptor)
+      val simpleFileFilter = new SimpleFileFilter(file => ignoreSupport.isIgnoredByFileOrPackages(file))
       simpleFileFilter || (excludeFilter in format).value
     }
   )
diff --git a/project/ProjectFileIgnoreSupport.scala b/project/ProjectFileIgnoreSupport.scala
index c847fe586c..988db7bf1d 100644
--- a/project/ProjectFileIgnoreSupport.scala
+++ b/project/ProjectFileIgnoreSupport.scala
@@ -7,37 +7,41 @@ package akka
 import java.io.File
 
 import com.typesafe.config.ConfigFactory
+import sbt.AutoPlugin
+import sbt.Def
 import sbt.file
 import sbt.internal.sbtscalafix.Compat
 
-trait ProjectFileIgnoreSupport {
-  protected val stdoutLogger = Compat.ConsoleLogger(System.out)
+class ProjectFileIgnoreSupport(ignoreConfigFile: File, descriptor: String) {
+  private val stdoutLogger = Compat.ConsoleLogger(System.out)
 
-  protected def ignoreConfigFileName: String
+  private lazy val ignoreConfig = {
+    require(ignoreConfigFile.exists(), s"Expected ignore configuration for $descriptor at ${ignoreConfigFile.getAbsolutePath} but was missing")
+    ConfigFactory.parseFile(ignoreConfigFile)
+  }
 
-  protected def descriptor: String
-
-  lazy val ignoredFiles: Set[String] = {
+  private lazy val ignoredFiles: Set[String] = {
     import scala.collection.JavaConverters._
-    val config = ConfigFactory.parseFile(file(ignoreConfigFileName))
-    stdoutLogger.debug(s"Loading ignored-files from $ignoreConfigFileName:[${config.origin().url().toURI.getPath}]")
-    config
+    stdoutLogger.debug(s"Loading ignored-files from $ignoreConfigFile:[${ignoreConfig.origin().url().toURI.getPath}]")
+    ignoreConfig
       .getStringList("ignored-files")
       .asScala
       .toSet
   }
 
-  lazy val ignoredPackages: Set[String] = {
+  private lazy val ignoredPackages: Set[String] = {
     import scala.collection.JavaConverters._
-    val config = ConfigFactory.parseFile(file(ignoreConfigFileName))
-    stdoutLogger.debug(s"Loading ignored-packages from $ignoreConfigFileName:[${config.origin().url().toURI.getPath}]")
-    config
+    stdoutLogger.debug(s"Loading ignored-packages from $ignoreConfigFile:[${ignoreConfig.origin().url().toURI.getPath}]")
+    ignoreConfig
       .getStringList("ignored-packages")
       .asScala
       .toSet
   }
 
-  protected def isIgnoredByFile(file: File): Boolean = {
+  def isIgnoredByFileOrPackages(file: File): Boolean =
+    isIgnoredByFile(file) || isIgnoredByPackages(file)
+
+  private def isIgnoredByFile(file: File): Boolean = {
     val ignoredByFile = ignoredFiles(file.getName)
     if (ignoredByFile) {
       stdoutLogger.debug(s"$descriptor ignored file with file name:${file.getName} file:[${file.toPath}]")
@@ -45,7 +49,7 @@ trait ProjectFileIgnoreSupport {
     ignoredByFile
   }
 
-  protected def isIgnoredByPackages(file: File): Boolean = {
+  private def isIgnoredByPackages(file: File): Boolean = {
     val ignoredByPackages = ignoredPackages.exists(pkg => {
       getPackageName(file.toURI.toString) match {
         case Some(packageName) =>
@@ -60,11 +64,7 @@ trait ProjectFileIgnoreSupport {
     ignoredByPackages
   }
 
-  protected def isIgnoredByFileOrPackages(file: File): Boolean = {
-    isIgnoredByFile(file) || isIgnoredByPackages(file)
-  }
-
-  protected def getPackageName(fileName: String): Option[String] = {
+  private def getPackageName(fileName: String): Option[String] = {
     def getPackageName0(fileType: String): String = {
       import java.io.{File => JFile}
       fileName.split(JFile.separatorChar)
diff --git a/project/ScalafixSupport.scala b/project/ScalafixSupport.scala
index 4795467631..49ab1377e4 100644
--- a/project/ScalafixSupport.scala
+++ b/project/ScalafixSupport.scala
@@ -3,22 +3,24 @@
  */
 
 package sbt
+import Keys.baseDirectory
 
 import akka.ProjectFileIgnoreSupport
 import sbt.Keys.unmanagedSources
 
-trait ScalafixSupport extends ProjectFileIgnoreSupport {
-
-  final override protected val ignoreConfigFileName: String = ".scalafix.conf"
-
-  final override protected val descriptor: String = "scalafix"
+trait ScalafixSupport {
+  private val ignoreConfigFileName: String = ".scalafix.conf"
+  private val descriptor: String = "scalafix"
 
   protected def ignore(configKey: ConfigKey): Def.Setting[Task[Seq[File]]] = {
     import scalafix.sbt.ScalafixPlugin.autoImport._
-    
-    unmanagedSources.in(configKey, scalafix) :=
+
+    unmanagedSources.in(configKey, scalafix) := {
+      val ignoreSupport = new ProjectFileIgnoreSupport((baseDirectory in ThisBuild).value / ignoreConfigFileName, descriptor)
+
       unmanagedSources.in(configKey, scalafix).value
-        .filterNot(file => isIgnoredByFileOrPackages(file))
+        .filterNot(file => ignoreSupport.isIgnoredByFileOrPackages(file))
+    }
   }