diff -r e27cfd2bf094 -r 0d4ee4168e41 src/Pure/Concurrent/event_timer.ML
--- a/src/Pure/Concurrent/event_timer.ML	Tue Nov 03 11:24:42 2015 +0100
+++ b/src/Pure/Concurrent/event_timer.ML	Tue Nov 03 13:54:34 2015 +0100
@@ -105,7 +105,7 @@
 fun manager_check manager =
   if is_some manager andalso Thread.isActive (the manager) then manager
   else
-    SOME (Simple_Thread.fork {name = "event_timer", stack_limit = NONE, interrupts = false}
+    SOME (Standard_Thread.fork {name = "event_timer", stack_limit = NONE, interrupts = false}
       manager_loop);
 
 fun shutdown () =