diff --git a/internal/util-logging/src/main/scala/sbt/internal/util/ConsoleOut.scala b/internal/util-logging/src/main/scala/sbt/internal/util/ConsoleOut.scala
index 17f74c53c..1f3e8e273 100644
--- a/internal/util-logging/src/main/scala/sbt/internal/util/ConsoleOut.scala
+++ b/internal/util-logging/src/main/scala/sbt/internal/util/ConsoleOut.scala
@@ -21,6 +21,13 @@ sealed trait ConsoleOut {
 
 object ConsoleOut {
   def systemOut: ConsoleOut = terminalOut
+  private[sbt] object NullConsoleOut extends ConsoleOut {
+    override val lockObject: AnyRef = this
+    override def print(s: String): Unit = {}
+    override def println(): Unit = {}
+    override def println(s: String): Unit = {}
+    override def flush(): Unit = {}
+  }
   private[sbt] def globalProxy: ConsoleOut = Proxy
   private[sbt] def setGlobalProxy(out: ConsoleOut): Unit = Proxy.set(out)
   private[sbt] def getGlobalProxy: ConsoleOut = Proxy.proxy.get
diff --git a/main/src/main/scala/sbt/internal/RelayAppender.scala b/main/src/main/scala/sbt/internal/RelayAppender.scala
index ed9355b37..2e61daa7c 100644
--- a/main/src/main/scala/sbt/internal/RelayAppender.scala
+++ b/main/src/main/scala/sbt/internal/RelayAppender.scala
@@ -15,7 +15,7 @@ import sbt.util.Level
 class RelayAppender(override val name: String)
     extends ConsoleAppender(
       name,
-      ConsoleAppender.Properties.from(ConsoleOut.globalProxy, true, true),
+      ConsoleAppender.Properties.from(ConsoleOut.NullConsoleOut, true, true),
       _ => None
     ) {
   lazy val exchange = StandardMain.exchange