diff --git a/core/classes/predicate/predicate-tests.factor b/core/classes/predicate/predicate-tests.factor
index 3de073f774..d4c929a69b 100644
--- a/core/classes/predicate/predicate-tests.factor
+++ b/core/classes/predicate/predicate-tests.factor
@@ -1,4 +1,4 @@
-USING: math tools.test classes.algebra ;
+USING: math tools.test classes.algebra words kernel sequences assocs ;
 IN: classes.predicate
 
 PREDICATE: negative < integer 0 < ;
@@ -19,3 +19,9 @@ M: positive abs ;
 [ 10 ] [ -10 abs ] unit-test
 [ 10 ] [ 10 abs ] unit-test
 [ 0 ] [ 0 abs ] unit-test
+
+PREDICATE: blah < word blah eq? ;
+
+[ f ] [ \ predicate-instance? "compiled-uses" word-prop keys \ blah swap memq? ] unit-test
+
+FORGET: blah
\ No newline at end of file
diff --git a/core/classes/predicate/predicate.factor b/core/classes/predicate/predicate.factor
index 4ba93acae4..7d757772f4 100644
--- a/core/classes/predicate/predicate.factor
+++ b/core/classes/predicate/predicate.factor
@@ -25,8 +25,9 @@ DEFER: predicate-instance? ( object class -- ? )
 : predicate-quot ( class -- quot )
     [
         \ dup ,
-        dup superclass "predicate" word-prop %
-        "predicate-definition" word-prop , [ drop f ] , \ if ,
+        [ superclass "predicate" word-prop % ]
+        [ "predicate-definition" word-prop , ] bi
+        [ drop f ] , \ if ,
     ] [ ] make ;
 
 : define-predicate-class ( class superclass definition -- )
@@ -42,9 +43,8 @@ DEFER: predicate-instance? ( object class -- ? )
     update-predicate-instance ;
 
 M: predicate-class reset-class
-    [ call-next-method ]
-    [ { "predicate-definition" } reset-props ]
-    bi ;
+    [ call-next-method ] [ { "predicate-definition" } reset-props ] bi
+    update-predicate-instance ;
 
 M: predicate-class rank-class drop 1 ;
 
diff --git a/core/classes/union/union-tests.factor b/core/classes/union/union-tests.factor
index 0802c0a2d9..57b742595f 100644
--- a/core/classes/union/union-tests.factor
+++ b/core/classes/union/union-tests.factor
@@ -70,10 +70,14 @@ UNION: redefine-bug-2 redefine-bug-1 quotation ;
 
 [ t ] [ "blah" "classes.union.tests" lookup union-class? ] unit-test
 
+[ t ] [ "foo?" "classes.union.tests" lookup predicate? ] unit-test
+
 [ ] [ "IN: classes.union.tests USE: math UNION: blah integer ;" <string-reader> "union-reset-test" parse-stream drop ] unit-test
 
 [ t ] [ "blah" "classes.union.tests" lookup union-class? ] unit-test
 
+[ f ] [ "foo?" "classes.union.tests" lookup predicate? ] unit-test
+
 GENERIC: test-generic ( x -- y )
 
 TUPLE: a-tuple ;