diff --git a/collects/typed-scheme/types/union.ss b/collects/typed-scheme/types/union.ss
index 5019cada..a78cbae0 100644
--- a/collects/typed-scheme/types/union.ss
+++ b/collects/typed-scheme/types/union.ss
@@ -19,6 +19,8 @@
 (define (flat t)
   (match t
     [(Union: es) es]
+    [(Values: (list (Result: (Union: es) _ _))) es]
+    [(Values: (list (Result: t _ _))) (list t)]
     [_ (list t)]))    
 
 (define (remove-subtypes ts)
diff --git a/collects/typed-scheme/utils/utils.ss b/collects/typed-scheme/utils/utils.ss
index 766ba3c2..8e3d6f73 100644
--- a/collects/typed-scheme/utils/utils.ss
+++ b/collects/typed-scheme/utils/utils.ss
@@ -160,7 +160,7 @@ at least theoretically.
 
 
 ;; turn contracts on and off - off by default for performance.
-(define-for-syntax enable-contracts? #t)
+(define-for-syntax enable-contracts? #f)
 (provide (for-syntax enable-contracts?) p/c w/c cnt d-s/c d/c)
 
 ;; these are versions of the contract forms conditionalized by `enable-contracts?'