diff --git a/build.sbt b/build.sbt
index a6c668f34f..b9b3cf9f39 100644
--- a/build.sbt
+++ b/build.sbt
@@ -54,7 +54,12 @@ lazy val root = Project(
   base = file(".")
 ).aggregate(aggregatedProjects: _*)
  .settings(rootSettings: _*)
- .settings(unidocRootIgnoreProjects := Seq(remoteTests, benchJmh, protobuf, akkaScalaNightly, docs))
+ .settings(unidocRootIgnoreProjects :=
+   (CrossVersion.partialVersion(scalaVersion.value) match {
+     case Some((2, n)) if n == 11 ⇒ aggregatedProjects // ignore all, don't unidoc when scalaVersion is 2.11
+     case _                       ⇒ Seq(remoteTests, benchJmh, protobuf, akkaScalaNightly, docs) 
+   })
+ )
  .settings(
    unmanagedSources in(Compile, headerCreate) := (baseDirectory.value / "project").**("*.scala").get
  )
diff --git a/project/Doc.scala b/project/Doc.scala
index cbe6cde30a..5e78e11140 100644
--- a/project/Doc.scala
+++ b/project/Doc.scala
@@ -5,7 +5,7 @@
 package akka
 
 import sbt._
-import sbtunidoc.BaseUnidocPlugin.autoImport.{ unidoc, unidocProjectFilter }
+import sbtunidoc.BaseUnidocPlugin.autoImport.{unidoc, unidocProjectFilter}
 import sbtunidoc.JavaUnidocPlugin.autoImport.JavaUnidoc
 import sbtunidoc.ScalaUnidocPlugin.autoImport.ScalaUnidoc
 import sbtunidoc.GenJavadocPlugin.autoImport._
@@ -13,6 +13,8 @@ import sbt.Keys._
 import sbt.File
 import scala.annotation.tailrec
 
+import sbt.ScopeFilter.ProjectFilter
+
 object Scaladoc extends AutoPlugin {
 
   object CliOptions {
@@ -100,7 +102,7 @@ object UnidocRoot extends AutoPlugin {
   }
 
   object autoImport {
-    val unidocRootIgnoreProjects = settingKey[Seq[Project]]("Projects to ignore when generating unidoc")
+    val unidocRootIgnoreProjects = settingKey[Seq[ProjectReference]]("Projects to ignore when generating unidoc")
   }
   import autoImport._
 
@@ -113,7 +115,7 @@ object UnidocRoot extends AutoPlugin {
     Seq(javacOptions in (JavaUnidoc, unidoc) := Seq("-Xdoclint:none"))).getOrElse(Nil)
 
   override lazy val projectSettings = {
-    def unidocRootProjectFilter(ignoreProjects: Seq[Project]) =
+    def unidocRootProjectFilter(ignoreProjects: Seq[ProjectReference]): ProjectFilter = 
       ignoreProjects.foldLeft(inAnyProject) { _ -- inProjects(_) }
 
     inTask(unidoc)(Seq(
diff --git a/project/build.properties b/project/build.properties
index 72f902892a..7c58a83abf 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -1 +1 @@
-sbt.version=1.2.7
+sbt.version=1.2.6