diff -r e57416b649d5 -r aa3b47b32100 src/Tools/Code/code_ml.ML
--- a/src/Tools/Code/code_ml.ML	Tue Mar 15 23:59:39 2016 +0100
+++ b/src/Tools/Code/code_ml.ML	Wed Mar 16 11:45:25 2016 +0100
@@ -871,7 +871,7 @@
       check = { env_var = "ISABELLE_TOOL",
         make_destination = fn p => Path.append p (Path.explode "ROOT.ML"),
         make_command = fn _ =>
-          "\"$ISABELLE_TOOL\" process -e 'datatype ref = datatype Unsynchronized.ref' -f 'ROOT.ML' Pure" } })
+          "\"$ISABELLE_TOOL\" process -e 'datatype ref = datatype Unsynchronized.ref' -f 'ROOT.ML' -l Pure" } })
   #> Code_Target.add_language
     (target_OCaml, { serializer = serializer_ocaml, literals = literals_ocaml,
       check = { env_var = "ISABELLE_OCAML",