diff --git a/collects/typed-scheme/private/colon.ss b/collects/typed-scheme/private/colon.ss
index 47b278cd..5e1776df 100644
--- a/collects/typed-scheme/private/colon.ss
+++ b/collects/typed-scheme/private/colon.ss
@@ -11,7 +11,7 @@
 (define-syntax (: stx)
   (define-syntax-class arr
     (pattern x:id
-             #:fail-unless (eq? (syntax-e #'x '->)) #f
+             #:fail-unless (eq? (syntax-e #'x) '->) #f
              #:fail-unless (printf "id: ~a ~a~n"
                                    (identifier-binding #'All-kw) 
                                    (identifier-transformer-binding #'All-kw)) 
diff --git a/collects/typed-scheme/typecheck/tc-metafunctions.ss b/collects/typed-scheme/typecheck/tc-metafunctions.ss
index 186c3250..435980a4 100644
--- a/collects/typed-scheme/typecheck/tc-metafunctions.ss
+++ b/collects/typed-scheme/typecheck/tc-metafunctions.ss
@@ -63,7 +63,8 @@
     [(FilterSet: f+ f-)
      (lcombine
       (apply append (for/list ([f f+]) (abo ids keys f)))
-      (apply append (for/list ([f f-]) (abo ids keys f))))]))
+      (apply append (for/list ([f f-]) (abo ids keys f))))]
+    [(NoFilter:) (lcombine null null)]))
 
 (d/c (abo xs idxs f)
   ((listof identifier?) (listof index/c) Filter/c . -> . (or/c null? (list/c LatentFilter/c)))