diff --git a/main/src/main/scala/sbt/internal/ShutdownHooks.scala b/main/src/main/scala/sbt/internal/ShutdownHooks.scala
index eb29674d1..02263706f 100644
--- a/main/src/main/scala/sbt/internal/ShutdownHooks.scala
+++ b/main/src/main/scala/sbt/internal/ShutdownHooks.scala
@@ -14,7 +14,7 @@ import scala.util.control.NonFatal
 
 private[sbt] object ShutdownHooks extends AutoCloseable {
   private[this] val idGenerator = new AtomicInteger(0)
-  private[this] val hooks = new ConcurrentHashMap[Int, () => Any]
+  private[this] val hooks = new ConcurrentHashMap[Int, () => Unit]
   private[this] val ranHooks = new AtomicBoolean(false)
   private[this] val thread = new Thread("shutdown-hooks-run-all") {
     override def run(): Unit = runAll()
@@ -26,8 +26,10 @@ private[sbt] object ShutdownHooks extends AutoCloseable {
     hooks.put(
       id,
       () =>
-        try task()
-        catch {
+        try {
+          task()
+          ()
+        } catch {
           case NonFatal(e) =>
             System.err.println(s"Caught exception running shutdown hook: $e")
             e.printStackTrace(System.err)
@@ -36,7 +38,7 @@ private[sbt] object ShutdownHooks extends AutoCloseable {
     () => Option(hooks.remove(id)).foreach(_.apply())
   }
   private def runAll(): Unit = if (ranHooks.compareAndSet(false, true)) {
-    hooks.forEachValue(Runtime.getRuntime.availableProcessors, _.apply())
+    hooks.forEachValue(runtime.availableProcessors.toLong, _.apply())
   }
   override def close(): Unit = {
     runtime.removeShutdownHook(thread)
diff --git a/main/src/main/scala/sbt/nio/Watch.scala b/main/src/main/scala/sbt/nio/Watch.scala
index d911c98dc..5eb4cf344 100644
--- a/main/src/main/scala/sbt/nio/Watch.scala
+++ b/main/src/main/scala/sbt/nio/Watch.scala
@@ -17,7 +17,6 @@ import sbt.BasicCommandStrings.ContinuousExecutePrefix
 import sbt._
 import sbt.internal.LabeledFunctions._
 import sbt.internal.nio.FileEvent
-import sbt.internal.util.Util
 import sbt.internal.util.complete.Parser
 import sbt.internal.util.complete.Parser._
 import sbt.nio.file.FileAttributes