diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 7634176757c..bbb22f67a1c 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+1998-10-04  Mark Mitchell  <mark@markmitchell.com>
+
+	* search.c (expand_upcast_vtables): In addition to unsetting 
+	TREE_READONLY, remove top-level const type qualifier.
+
 1998-10-03  Mark Mitchell  <mark@markmitchell.com>
 
 	* class.c (current_class_ptr, current_class_ref): Clarify
diff --git a/gcc/cp/search.c b/gcc/cp/search.c
index 3c04170facb..75c3d198a1d 100644
--- a/gcc/cp/search.c
+++ b/gcc/cp/search.c
@@ -2588,6 +2588,9 @@ expand_upcast_fixups (binfo, addr, orig_addr, vbase, vbase_addr, t,
 	    }
 
 	  TREE_READONLY (new_delta) = 0;
+	  TREE_TYPE (new_delta) = 
+	    cp_build_type_variant (TREE_TYPE (new_delta), /*constp=*/0,
+				   TYPE_VOLATILE (TREE_TYPE (new_delta)));
 	  expand_expr_stmt (build_modify_expr (new_delta, NOP_EXPR,
 					       old_delta));
 	}