diff -r f6a2e5ce2ce5 -r 5f5649ac8235 src/Pure/Thy/thy_header.ML
--- a/src/Pure/Thy/thy_header.ML	Sun Aug 21 20:25:49 2011 +0200
+++ b/src/Pure/Thy/thy_header.ML	Sun Aug 21 20:42:26 2011 +0200
@@ -29,8 +29,8 @@
 
 (* header args *)
 
-val file_name = Parse.group "file name" Parse.name;
-val theory_name = Parse.group "theory name" Parse.name;
+val file_name = Parse.group (fn () => "file name") Parse.name;
+val theory_name = Parse.group (fn () => "theory name") Parse.name;
 
 val file =
   Parse.$$$ "(" |-- Parse.!!! (file_name --| Parse.$$$ ")") >> rpair false ||