diff -r af131b9af420 -r 43e64c770f28 src/Tools/Code/code_ml.ML
--- a/src/Tools/Code/code_ml.ML	Mon Feb 29 16:38:06 2016 +0100
+++ b/src/Tools/Code/code_ml.ML	Mon Feb 29 20:35:06 2016 +0100
@@ -869,7 +869,7 @@
       check = { env_var = "ISABELLE_PROCESS",
         make_destination = fn p => Path.append p (Path.explode "ROOT.ML"),
         make_command = fn _ =>
-          "\"$ISABELLE_PROCESS\" -r -q -e 'datatype ref = datatype Unsynchronized.ref; use \"ROOT.ML\" handle _ => exit 1' Pure" } })
+          "\"$ISABELLE_PROCESS\" -q -e 'datatype ref = datatype Unsynchronized.ref; use \"ROOT.ML\" handle _ => exit 1' Pure" } })
   #> Code_Target.add_language
     (target_OCaml, { serializer = serializer_ocaml, literals = literals_ocaml,
       check = { env_var = "ISABELLE_OCAML",