diff --git a/cache/tracking/src/main/scala/sbt/Tracked.scala b/cache/tracking/src/main/scala/sbt/Tracked.scala
index 5965fc135..0de466686 100644
--- a/cache/tracking/src/main/scala/sbt/Tracked.scala
+++ b/cache/tracking/src/main/scala/sbt/Tracked.scala
@@ -38,7 +38,8 @@ object Tracked {
       toFile(next)(cacheFile)
       next
     }
-  private[sbt] def lastOuputWithJson[I, O: Pickler: Unpickler](cacheFile: File)(f: (I, Option[O]) => O): I => O = in =>
+  // Todo: This function needs more testing.
+  private[sbt] def lastOutputWithJson[I, O: Pickler: Unpickler](cacheFile: File)(f: (I, Option[O]) => O): I => O = in =>
     {
       val previous: Option[O] = try {
         fromJsonFile[O](cacheFile).toOption
diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index bb12ba97b..44b4062c5 100755
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -1388,13 +1388,13 @@ object Classpaths {
 
       val outCacheFile = cacheFile / "output"
       def skipWork: In => UpdateReport =
-        Tracked.lastOuputWithJson[In, UpdateReport](outCacheFile) {
+        Tracked.lastOutput[In, UpdateReport](outCacheFile) {
           case (_, Some(out)) => out
           case _              => sys.error("Skipping update requested, but update has not previously run successfully.")
         }
       def doWork: In => UpdateReport =
         Tracked.inputChanged(cacheFile / "inputs") { (inChanged: Boolean, in: In) =>
-          val outCache = Tracked.lastOuputWithJson[In, UpdateReport](outCacheFile) {
+          val outCache = Tracked.lastOutput[In, UpdateReport](outCacheFile) {
             case (_, Some(out)) if uptodate(inChanged, out) => out
             case _ => work(in)
           }