diff -r 0070053570c4 -r 71b416020f42 src/Tools/Code/code_runtime.ML
--- a/src/Tools/Code/code_runtime.ML	Thu Dec 18 21:10:39 2014 +0100
+++ b/src/Tools/Code/code_runtime.ML	Fri Dec 19 12:36:50 2014 +0100
@@ -336,7 +336,8 @@
 (
   type T = (string list * string list) * (bool
     * (string * (string * string) list) lazy);
-  fun init _ = (([], []), (true, (Lazy.value ("", []))));
+  val empty: T = (([], []), (true, (Lazy.value ("", []))));
+  fun init _ = empty;
 );
 
 val is_first_occ = fst o snd o Code_Antiq_Data.get;