diff --git a/extra/compiler/cfg/gvn/avail/avail.factor b/extra/compiler/cfg/gvn/avail/avail.factor
index 906646281c..768850df8b 100644
--- a/extra/compiler/cfg/gvn/avail/avail.factor
+++ b/extra/compiler/cfg/gvn/avail/avail.factor
@@ -1,7 +1,7 @@
 ! Copyright (C) 2011 Alex Vondrak.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors assocs hashtables kernel namespaces sequences
-sequences.extras sets
+sets
 compiler.cfg
 compiler.cfg.dataflow-analysis
 compiler.cfg.def-use
@@ -24,9 +24,12 @@ M: avail transfer-set drop defined assoc-union ;
 
 : available? ( vn -- ? ) basic-block get avail-in key? ;
 
+: best-vreg ( available-vregs -- vreg )
+    [ f ] [ infimum ] if-empty ;
+
 : >avail-vreg ( vreg -- vreg/f )
     final-iteration? get [
-        congruence-class [ available? ] filter ?infimum
+        congruence-class [ available? ] filter best-vreg
     ] when ;
 
 : available-uses? ( insn -- ? )