src/Pure/axclass.ML

--- a/src/Pure/axclass.ML	Wed Dec 20 20:58:56 2023 +0100
+++ b/src/Pure/axclass.ML	Wed Dec 20 22:32:57 2023 +0100
@@ -161,7 +161,8 @@
 
 fun inst_thms ctxt =
   Symtab.fold
-    (Symtab.fold (cons o #2 o #2) o #2) (#1 (inst_params_of (Proof_Context.theory_of ctxt))) [];
+    (Symtab.fold (cons o #2 o #2) o #2) (#1 (inst_params_of (Proof_Context.theory_of ctxt))) []
+  |> map (Thm.transfer' ctxt);
 
 fun get_inst_tyco consts = try (#1 o dest_Type o the_single o Consts.typargs consts);