diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index cc72580f5..d98bed654 100755
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -250,7 +250,7 @@ object Defaults extends BuildCommon {
       },
       trapExit :== true,
       connectInput :== false,
-      cancelable :== false,
+      cancelable :== true,
       taskCancelStrategy := { state: State =>
         if (cancelable.value) TaskCancellationStrategy.Signal
         else TaskCancellationStrategy.Null