diff -r dac4e2bce00d -r 9283b4185fdf src/Pure/assumption.ML
--- a/src/Pure/assumption.ML	Fri Mar 28 19:43:54 2008 +0100
+++ b/src/Pure/assumption.ML	Fri Mar 28 20:02:04 2008 +0100
@@ -79,8 +79,8 @@
 (* named prems -- legacy feature *)
 
 val _ = Context.>>
-  (PureThy.add_thms_dynamic ("prems",
-    fn Context.Theory _ => [] | Context.Proof ctxt => prems_of ctxt));
+  (Context.map_theory (PureThy.add_thms_dynamic ("prems",
+    fn Context.Theory _ => [] | Context.Proof ctxt => prems_of ctxt)));
 
 
 (* add assumptions *)