diff --git a/main/settings/src/main/scala/sbt/std/TaskMacro.scala b/main/settings/src/main/scala/sbt/std/TaskMacro.scala
index 6c48613dd..76392716b 100644
--- a/main/settings/src/main/scala/sbt/std/TaskMacro.scala
+++ b/main/settings/src/main/scala/sbt/std/TaskMacro.scala
@@ -18,7 +18,7 @@ object TaskInstance extends MonadInstance {
   import TaskExtra._
 
   final type M[x] = Task[x]
-  def app[K[L[x]], Z](in: K[Task], f: K[Id] => Z)(implicit a: AList[K]): Task[Z] = Task(Info(), new Mapped[Z, K](in, f compose allM, a))
+  def app[K[L[x]], Z](in: K[Task], f: K[Id] => Z)(implicit a: AList[K]): Task[Z] = in map f
   def map[S, T](in: Task[S], f: S => T): Task[T] = in map f
   def flatten[T](in: Task[Task[T]]): Task[T] = in flatMap idFun[Task[T]]
   def pure[T](t: () => T): Task[T] = toTask(t)
diff --git a/sbt/src/sbt-test/actions/depends-on/build.sbt b/sbt/src/sbt-test/actions/depends-on/build.sbt
index c20f79671..8a319ce52 100644
--- a/sbt/src/sbt-test/actions/depends-on/build.sbt
+++ b/sbt/src/sbt-test/actions/depends-on/build.sbt
@@ -14,7 +14,7 @@ lazy val d = taskKey[Unit]("")
 
 lazy val input = (project in file("input")).
   settings(
-    f := (inputTask { _ map { args => if (args(0) == "succeed") () else sys.error("fail") } }).evaluated,
+    f := (if (Def.spaceDelimited().parsed.head == "succeed") () else sys.error("fail")),
     j := sys.error("j"),
     g := (f dependsOn(j)).evaluated,
     h := (f map { _ => IO.touch(file("h")) }).evaluated
diff --git a/sbt/src/sbt-test/actions/task-map/build.sbt b/sbt/src/sbt-test/actions/task-map/build.sbt
new file mode 100644
index 000000000..34c26b3b9
--- /dev/null
+++ b/sbt/src/sbt-test/actions/task-map/build.sbt
@@ -0,0 +1,38 @@
+val taskA = taskKey[File]("")
+val taskB = taskKey[File]("")
+val taskC = taskKey[File]("")
+val taskD = taskKey[File]("")
+
+val taskE = taskKey[File]("")
+val taskF = taskKey[File]("")
+val taskG = taskKey[File]("")
+val taskH = taskKey[File]("")
+
+taskA := touch(target.value / "a")
+taskB := touch(target.value / "b")
+taskC := touch(target.value / "c")
+taskD := touch(target.value / "d")
+
+taskE := touch(target.value / "e")
+taskF := touch(target.value / "f")
+taskG := touch(target.value / "g")
+taskH := touch(target.value / "h")
+
+//   a <<= a triggeredBy b
+// means "a" will be triggered by "b"
+// said differently, invoking "b" will run "b" and then run "a"
+
+taskA <<= taskA triggeredBy taskB
+taskC := (taskC triggeredBy taskD).value
+
+//   e <<= e runBefore f
+// means "e" will be run before running "f"
+// said differently, invoking "f" will run "e" and then run "f"
+
+taskE <<= taskE runBefore taskF
+taskG := (taskG runBefore taskH).value
+
+
+
+// test utils
+def touch(f: File): File = { IO touch f; f }
diff --git a/sbt/src/sbt-test/actions/task-map/test b/sbt/src/sbt-test/actions/task-map/test
new file mode 100644
index 000000000..0617f3abe
--- /dev/null
+++ b/sbt/src/sbt-test/actions/task-map/test
@@ -0,0 +1,15 @@
+> taskB
+$ exists target/b
+$ exists target/a
+
+> taskD
+$ exists target/d
+$ exists target/c
+
+> taskF
+$ exists target/e
+$ exists target/f
+
+> taskH
+$ exists target/g
+$ exists target/h
diff --git a/tasks/standard/src/main/scala/sbt/std/TaskExtra.scala b/tasks/standard/src/main/scala/sbt/std/TaskExtra.scala
index 10914daee..716686241 100644
--- a/tasks/standard/src/main/scala/sbt/std/TaskExtra.scala
+++ b/tasks/standard/src/main/scala/sbt/std/TaskExtra.scala
@@ -117,9 +117,14 @@ trait TaskExtra {
     def failure: Task[Incomplete] = mapFailure(idFun)
     def result: Task[Result[S]] = mapR(idFun)
 
-    def flatMapR[T](f: Result[S] => Task[T]): Task[T] = Task(Info(), new FlatMapped[T, K](in, f, ml))
-    def mapR[T](f: Result[S] => T): Task[T] = Task(Info(), new Mapped[T, K](in, f, ml))
-    def dependsOn(tasks: Task[_]*): Task[S] = Task(Info(), new DependsOn(in, tasks))
+    // The "taskDefinitionKey" is used, at least, by the ".previous" functionality.
+    // But apparently it *cannot* survive a task map/flatMap/etc. See actions/depends-on.
+    private def newInfo[A]: Info[A] =
+      Info[A](AttributeMap(in.info.attributes.entries.filter(_.key.label != "taskDefinitionKey")))
+
+    def flatMapR[T](f: Result[S] => Task[T]): Task[T] = Task(newInfo, new FlatMapped[T, K](in, f, ml))
+    def mapR[T](f: Result[S] => T): Task[T] = Task(newInfo, new Mapped[T, K](in, f, ml))
+    def dependsOn(tasks: Task[_]*): Task[S] = Task(newInfo, new DependsOn(in, tasks))
 
     def flatMap[T](f: S => Task[T]): Task[T] = flatMapR(f compose successM)
     def flatFailure[T](f: Incomplete => Task[T]): Task[T] = flatMapR(f compose failM)