diff --git a/main/Build.scala b/main/Build.scala
index 26b8c62ee..f5273e2d5 100644
--- a/main/Build.scala
+++ b/main/Build.scala
@@ -166,9 +166,13 @@ object Index
 			(value, ScopedKey(scope, key.asInstanceOf[AttributeKey[Task[_]]])) // unclear why this cast is needed even with a type test in the above filter
 		pairs.toMap[Task[_], ScopedKey[Task[_]]]
 	}
-	def stringToKeyMap(settings: Settings[Scope]): Map[String, AttributeKey[_]] =
+	def allKeys(settings: Seq[Setting[_]]): Set[ScopedKey[_]] =
+		settings.flatMap(s => s.key +: s.dependsOn).toSet
+	def attributeKeys(settings: Settings[Scope]): Set[AttributeKey[_]] =
+		settings.data.values.flatMap(_.keys).toSet[AttributeKey[_]]
+	def stringToKeyMap(settings: Set[AttributeKey[_]]): Map[String, AttributeKey[_]] =	
 	{
-		val multiMap = settings.data.values.flatMap(_.keys).toSet[AttributeKey[_]].groupBy(_.label)
+		val multiMap = settings.groupBy(_.label)
 		val duplicates = multiMap collect { case (k, xs) if xs.size > 1 => (k, xs.map(_.manifest)) } collect { case (k, xs) if xs.size > 1 => (k, xs) }
 		if(duplicates.isEmpty)
 			multiMap.collect { case (k, v) if validID(k) => (k, v.head) } toMap;
diff --git a/main/KeyIndex.scala b/main/KeyIndex.scala
index 78955d9f3..a4a5794ee 100644
--- a/main/KeyIndex.scala
+++ b/main/KeyIndex.scala
@@ -11,7 +11,7 @@ package sbt
 object KeyIndex
 {
 	def empty: ExtendableKeyIndex = new KeyIndex0(emptyBuildIndex)
-	def apply(known: Seq[ScopedKey[_]]): ExtendableKeyIndex =
+	def apply(known: Iterable[ScopedKey[_]]): ExtendableKeyIndex =
 		(empty /: known) { _ add _ }
 	def combine(indices: Seq[KeyIndex]): KeyIndex = new KeyIndex {
 		def buildURIs = concat(_.buildURIs)
diff --git a/main/Load.scala b/main/Load.scala
index 753dda16d..db4cf6fa4 100644
--- a/main/Load.scala
+++ b/main/Load.scala
@@ -121,7 +121,7 @@ object Load
 		val settings = finalTransforms(buildConfigurations(loaded, getRootProject(projects), rootEval, config.injectSettings))
 		val delegates = config.delegates(loaded)
 		val data = Project.makeSettings(settings, delegates, config.scopeLocal)
-		val index = structureIndex(data)
+		val index = structureIndex(data, settings)
 		val streams = mkStreams(projects, loaded.root, data)
 		(rootEval, new BuildStructure(projects, loaded.root, settings, data, index, streams, delegates, config.scopeLocal))
 	}
@@ -160,15 +160,20 @@ object Load
 	def setDefinitionKey[T](tk: Task[T], key: ScopedKey[_]): Task[T] =
 		if(isDummy(tk)) tk else Task(tk.info.set(Keys.taskDefinitionKey, key), tk.work)
 
-	def structureIndex(settings: Settings[Scope]): StructureIndex =
-		new StructureIndex(Index.stringToKeyMap(settings), Index.taskToKeyMap(settings), Index.triggers(settings), KeyIndex(settings.allKeys( (s,k) => ScopedKey(s,k))))
+	def structureIndex(data: Settings[Scope], settings: Seq[Setting[_]]): StructureIndex =
+	{
+		val keys = Index.allKeys(settings)
+		val attributeKeys = Index.attributeKeys(data) ++ keys.map(_.key)
+		val scopedKeys = keys ++ data.allKeys( (s,k) => ScopedKey(s,k))
+		new StructureIndex(Index.stringToKeyMap(attributeKeys), Index.taskToKeyMap(data), Index.triggers(data), KeyIndex(scopedKeys))
+	}
 
 		// Reevaluates settings after modifying them.  Does not recompile or reload any build components.
 	def reapply(newSettings: Seq[Setting[_]], structure: BuildStructure): BuildStructure =
 	{
 		val transformed = finalTransforms(newSettings)
 		val newData = Project.makeSettings(transformed, structure.delegates, structure.scopeLocal)
-		val newIndex = structureIndex(newData)
+		val newIndex = structureIndex(newData, transformed)
 		val newStreams = mkStreams(structure.units, structure.root, newData)
 		new BuildStructure(units = structure.units, root = structure.root, settings = transformed, data = newData, index = newIndex, streams = newStreams, delegates = structure.delegates, scopeLocal = structure.scopeLocal)
 	}