diff -r c3f07c950116 -r db9c6be8e236 src/Pure/Concurrent/delay.scala
--- a/src/Pure/Concurrent/delay.scala	Tue Mar 05 15:58:45 2024 +0100
+++ b/src/Pure/Concurrent/delay.scala	Tue Mar 05 16:06:06 2024 +0100
@@ -9,11 +9,11 @@
 
 object Delay {
   // delayed event after first invocation
-  def first(delay: => Time, log: Logger = No_Logger, gui: Boolean = false)(event: => Unit): Delay =
+  def first(delay: => Time, log: Logger = new Logger, gui: Boolean = false)(event: => Unit): Delay =
     new Delay(true, delay, log, if (gui) GUI_Thread.later { event } else event )
 
   // delayed event after last invocation
-  def last(delay: => Time, log: Logger = No_Logger, gui: Boolean = false)(event: => Unit): Delay =
+  def last(delay: => Time, log: Logger = new Logger, gui: Boolean = false)(event: => Unit): Delay =
     new Delay(false, delay, log, if (gui) GUI_Thread.later { event } else event )
 }