diff --git a/unfinished/compiler/tree/propagation/constraints/constraints.factor b/unfinished/compiler/tree/propagation/constraints/constraints.factor
index f6495d2998..46a9fc91ff 100644
--- a/unfinished/compiler/tree/propagation/constraints/constraints.factor
+++ b/unfinished/compiler/tree/propagation/constraints/constraints.factor
@@ -1,7 +1,7 @@
 ! Copyright (C) 2008 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: arrays assocs math math.intervals kernel accessors
-sequences namespaces disjoint-sets classes classes.algebra
+sequences namespaces classes classes.algebra
 combinators words
 compiler.tree compiler.tree.propagation.info
 compiler.tree.copy-equiv ;
diff --git a/unfinished/compiler/tree/propagation/known-words/known-words.factor b/unfinished/compiler/tree/propagation/known-words/known-words.factor
index 08fdb36cae..89d4cd690d 100644
--- a/unfinished/compiler/tree/propagation/known-words/known-words.factor
+++ b/unfinished/compiler/tree/propagation/known-words/known-words.factor
@@ -200,6 +200,12 @@ generic-comparison-ops [
 : info-classes-intersect? ( info1 info2 -- ? )
     [ class>> ] bi@ classes-intersect? ;
 
+\ eq? [
+    over value-info literal>> fixnum? [
+        [ value-info literal>> is-equal-to ] dip t-->
+    ] [ 3drop f ] if
+] +constraints+ set-word-prop
+
 \ eq? [
     [ info-intervals-intersect? ]
     [ info-classes-intersect? ]
diff --git a/unfinished/compiler/tree/propagation/propagation-tests.factor b/unfinished/compiler/tree/propagation/propagation-tests.factor
index c6e7865c48..0036f7bcc1 100644
--- a/unfinished/compiler/tree/propagation/propagation-tests.factor
+++ b/unfinished/compiler/tree/propagation/propagation-tests.factor
@@ -324,6 +324,10 @@ cell-bits 32 = [
 
 [ V{ t } ] [ [ [ 1 f <array> ] [ 2 f <array> ] if length 3 < ] final-literals ] unit-test
 
+[ V{ 10 } ] [
+    [ { fixnum } declare dup 10 = [ "A" throw ] unless ] final-literals
+] unit-test
+
 ! Slot propagation
 TUPLE: prop-test-tuple { x integer } ;
 
@@ -528,3 +532,7 @@ M: array iterate first t ;
 [ V{ fixnum } ] [
     [ { fixnum fixnum } declare [ nth-unsafe ] curry call ] final-classes
 ] unit-test
+
+[ V{ f } ] [
+    [ 10 eq? [ drop 3 ] unless ] final-literals
+] unit-test