diff --git a/main/src/main/scala/sbt/Load.scala b/main/src/main/scala/sbt/Load.scala
index 2f8cd79e1..cdad4edcb 100755
--- a/main/src/main/scala/sbt/Load.scala
+++ b/main/src/main/scala/sbt/Load.scala
@@ -468,7 +468,7 @@ object Load {
         plugs.detected.builds.values
       }
       val buildLevelExtraProjects = plugs.detected.autoPlugins flatMap { d =>
-        d.value.buildExtras map {_.setProjectOrigin(ProjectOrigin.BuildExtra)}
+        d.value.extraProjects map {_.setProjectOrigin(ProjectOrigin.ExtraProject)}
       }
 
       // NOTE - because we create an eval here, we need a clean-eval later for this URI.
@@ -602,7 +602,7 @@ object Load {
           }
         val p2 = this.resolveProject(p1, autoPlugins, plugins, injectSettings, memoSettings, log)
         val projectLevelExtra =
-          if (expand) autoPlugins flatMap { _.projectExtras(p2) map {_.setProjectOrigin(ProjectOrigin.ProjectExtra)} }
+          if (expand) autoPlugins flatMap { _.derivedProjects(p2) map {_.setProjectOrigin(ProjectOrigin.DerivedProject)} }
           else Nil
         (p2, projectLevelExtra)
       }
diff --git a/main/src/main/scala/sbt/Plugins.scala b/main/src/main/scala/sbt/Plugins.scala
index 3d550b20d..615ce32dc 100644
--- a/main/src/main/scala/sbt/Plugins.scala
+++ b/main/src/main/scala/sbt/Plugins.scala
@@ -91,10 +91,10 @@ abstract class AutoPlugin extends Plugins.Basic with PluginsFunctions {
   // TODO?: def commands: Seq[Command]
 
   /** The [[Project]]s to add to the current build. */
-  def buildExtras: Seq[Project] = Nil
+  def extraProjects: Seq[Project] = Nil
 
   /** The [[Project]]s to add to the current build based on an existing project. */
-  def projectExtras(proj: ProjectDefinition[_]): Seq[Project] = Nil
+  def derivedProjects(proj: ProjectDefinition[_]): Seq[Project] = Nil
 
   private[sbt] def unary_! : Exclude = Exclude(this)
 
diff --git a/main/src/main/scala/sbt/Project.scala b/main/src/main/scala/sbt/Project.scala
index d42a503f0..917d2442f 100755
--- a/main/src/main/scala/sbt/Project.scala
+++ b/main/src/main/scala/sbt/Project.scala
@@ -207,10 +207,10 @@ final case class ClasspathDependency(project: ProjectReference, configuration: O
  */
 sealed trait ProjectOrigin
 object ProjectOrigin {
-  case object Organic      extends ProjectOrigin
-  case object BuildExtra   extends ProjectOrigin
-  case object ProjectExtra extends ProjectOrigin
-  case object GenericRoot  extends ProjectOrigin
+  case object Organic        extends ProjectOrigin
+  case object ExtraProject   extends ProjectOrigin
+  case object DerivedProject extends ProjectOrigin
+  case object GenericRoot    extends ProjectOrigin
 }
 
 object Project extends ProjectExtra {
diff --git a/notes/0.13.13/extras.md b/notes/0.13.13/extras.md
index c53a97f8d..1ad735597 100644
--- a/notes/0.13.13/extras.md
+++ b/notes/0.13.13/extras.md
@@ -2,14 +2,14 @@
 ### Synthetic subprojects
 
 sbt 0.13.13 adds support for `AutoPlugin`s to generate
-synthetic subprojects. To generate subprojects, override `buildExtras`
+synthetic subprojects. To generate subprojects, override `extraProjects`
 method as follows:
 
     import sbt._
     import Keys._
 
-    object BuildExtrasPlugin extends AutoPlugin {
-      override def buildExtras: Seq[Project] =
+    object ExtraProjectPluginExample extends AutoPlugin {
+      override def extraProjects: Seq[Project] =
         List("foo", "bar", "baz") map generateProject
 
       def generateProject(id: String): Project =
@@ -20,19 +20,19 @@ method as follows:
     }
 
 In addition, subprojects may be derived from an existing subproject
-by overriding `projectExtras`.
+by overriding `derivedProjects`.
 
     import sbt._
     import Keys._
 
-    object ProjectExtrasPlugin extends AutoPlugin {
+    object ExtraProjectPluginExample2 extends AutoPlugin {
       // Enable this plugin by default
       override def requires: Plugins = sbt.plugins.CorePlugin
       override def trigger = allRequirements
 
-      override def projectExtras(proj: ProjectDefinition[_]): Seq[Project] =
+      override def derivedProjects(proj: ProjectDefinition[_]): Seq[Project] =
         // Make sure to exclude project extras to avoid recursive generation
-        if (proj.projectOrigin != ProjectOrigin.ProjectExtra) {
+        if (proj.projectOrigin != ProjectOrigin.DerivedProject) {
           val id = proj.id + "1"
           Seq(
             Project(id, file(id)).
diff --git a/sbt/src/sbt-test/project/extra-projects/project/BuildExtras.scala b/sbt/src/sbt-test/project/extra-projects/project/ExtraProjectPluginExample.scala
similarity index 66%
rename from sbt/src/sbt-test/project/extra-projects/project/BuildExtras.scala
rename to sbt/src/sbt-test/project/extra-projects/project/ExtraProjectPluginExample.scala
index 703f518ff..f63515944 100644
--- a/sbt/src/sbt-test/project/extra-projects/project/BuildExtras.scala
+++ b/sbt/src/sbt-test/project/extra-projects/project/ExtraProjectPluginExample.scala
@@ -1,8 +1,8 @@
 import sbt._
 import Keys._
 
-object BuildExtrasPlugin extends AutoPlugin {
-  override def buildExtras: Seq[Project] =
+object ExtraProjectPluginExample extends AutoPlugin {
+  override def extraProjects: Seq[Project] =
     List("foo", "bar", "baz") map generateProject
 
   def generateProject(id: String): Project =
diff --git a/sbt/src/sbt-test/project/extra-projects/project/ProjectExtrasPlugin.scala b/sbt/src/sbt-test/project/extra-projects/project/ExtraProjectPluginExample2.scala
similarity index 66%
rename from sbt/src/sbt-test/project/extra-projects/project/ProjectExtrasPlugin.scala
rename to sbt/src/sbt-test/project/extra-projects/project/ExtraProjectPluginExample2.scala
index 016386b28..a04004b33 100644
--- a/sbt/src/sbt-test/project/extra-projects/project/ProjectExtrasPlugin.scala
+++ b/sbt/src/sbt-test/project/extra-projects/project/ExtraProjectPluginExample2.scala
@@ -1,14 +1,14 @@
 import sbt._
 import Keys._
 
-object ProjectExtrasPlugin extends AutoPlugin {
+object ExtraProjectPluginExample2 extends AutoPlugin {
   // Enable this plugin by default
   override def requires: Plugins = sbt.plugins.CorePlugin
   override def trigger = allRequirements
 
-  override def projectExtras(proj: ProjectDefinition[_]): Seq[Project] =
+  override def derivedProjects(proj: ProjectDefinition[_]): Seq[Project] =
     // Make sure to exclude project extras to avoid recursive generation
-    if (proj.projectOrigin != ProjectOrigin.ProjectExtra) {
+    if (proj.projectOrigin != ProjectOrigin.DerivedProject) {
       val id = proj.id + "1"
       Seq(
         Project(id, file(id)).