diff --git a/basis/compiler/cfg/ssa/construction/tdmsc/tdmsc.factor b/basis/compiler/cfg/ssa/construction/tdmsc/tdmsc.factor
index ae3a20e800..7601ccc9bb 100644
--- a/basis/compiler/cfg/ssa/construction/tdmsc/tdmsc.factor
+++ b/basis/compiler/cfg/ssa/construction/tdmsc/tdmsc.factor
@@ -1,9 +1,9 @@
 ! Copyright (C) 2009 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors arrays assocs bit-arrays bit-sets fry
-hashtables hints kernel locals math namespaces sequences sets
+hashtables hints kernel locals math namespaces sequences new-sets
 compiler.cfg compiler.cfg.dominance compiler.cfg.rpo ;
-QUALIFIED: new-sets
+FROM: namespaces => set ;
 IN: compiler.cfg.ssa.construction.tdmsc
 
 ! TDMSC-I algorithm from "A Practical and Fast Iterative Algorithm for
@@ -34,8 +34,8 @@ SYMBOLS: visited merge-sets levels again? ;
     [ merge-sets get ] dip
     '[
         _
-        [ merge-sets get at new-sets:union ]
-        [ number>> over new-sets:adjoin ]
+        [ merge-sets get at union ]
+        [ number>> over adjoin ]
         bi
     ] change-at ;
 
@@ -49,10 +49,10 @@ SYMBOLS: visited merge-sets levels again? ;
     [ [ predecessors>> ] keep ] dip
     '[ _ 2dup j-edge? _ [ 2drop ] if ] each ; inline
 
-: visited? ( pair -- ? ) visited get key? ;
+: visited? ( pair -- ? ) visited get in? ;
 
 : consistent? ( snode lnode -- ? )
-    [ merge-sets get at ] bi@ new-sets:subset? ;
+    [ merge-sets get at ] bi@ subset? ;
 
 : (process-edge) ( from to -- )
     f walk [
@@ -63,7 +63,7 @@ SYMBOLS: visited merge-sets levels again? ;
 
 : process-edge ( from to -- )
     2dup 2array dup visited? [ 3drop ] [
-        visited get conjoin
+        visited get adjoin
         (process-edge)
     ] if ;
 
@@ -71,7 +71,7 @@ SYMBOLS: visited merge-sets levels again? ;
     [ process-edge ] each-incoming-j-edge ;
 
 : compute-merge-set-step ( bfo -- )
-    visited get clear-assoc
+    HS{ } clone visited set
     [ process-block ] each ;
 
 : compute-merge-set-loop ( cfg -- )
@@ -80,7 +80,7 @@ SYMBOLS: visited merge-sets levels again? ;
     loop ;
 
 : (merge-set) ( bbs -- flags rpo )
-    merge-sets get '[ _ at ] [ new-sets:union ] map-reduce
+    merge-sets get '[ _ at ] [ union ] map-reduce
     cfg get reverse-post-order ; inline
 
 PRIVATE>
@@ -88,14 +88,14 @@ PRIVATE>
 : compute-merge-sets ( cfg -- )
     needs-dominance
 
-    H{ } clone visited set
+    HS{ } clone visited set
     [ compute-levels ]
     [ init-merge-sets ]
     [ compute-merge-set-loop ]
     tri ;
 
 : merge-set ( bbs -- bbs' )
-     (merge-set) [ new-sets:members ] dip nths ;
+     (merge-set) [ members ] dip nths ;
 
 : merge-set-each ( bbs quot: ( bb -- ) -- )
     [ merge-set ] dip each ; inline