diff -r 902ccccf2efa -r 0eb9b5d09f31 src/Pure/System/isabelle_process.ML
--- a/src/Pure/System/isabelle_process.ML	Wed Nov 28 19:19:39 2012 +0100
+++ b/src/Pure/System/isabelle_process.ML	Thu Nov 29 10:45:25 2012 +0100
@@ -217,7 +217,7 @@
   protocol_command "Isabelle_Process.options"
     (fn [options_yxml] =>
       let val options = Options.decode (YXML.parse_body options_yxml) in
-        ML_Statistics.enabled := Options.bool options "ML_statistics";
+        Future.ML_statistics := Options.bool options "ML_statistics";
         Multithreading.trace := Options.int options "threads_trace";
         Multithreading.max_threads := Options.int options "threads";
         if Multithreading.max_threads_value () < 2