diff --git a/collects/typed-scheme/base-env/base-special-env.rkt b/collects/typed-scheme/base-env/base-special-env.rkt
index 39a2b4ee..ee27d504 100644
--- a/collects/typed-scheme/base-env/base-special-env.rkt
+++ b/collects/typed-scheme/base-env/base-special-env.rkt
@@ -26,7 +26,6 @@
              (initialize-type-env initial-env))
            (provide (for-syntax initialize-env))))]))
 
-
 (define-initial-env initialize-special
   ;; make-promise
   [(syntax-parse (local-expand #'(delay 3) 'expression null)
@@ -50,8 +49,7 @@
   [(syntax-parse (local-expand #'(for ([x '()]) x) 'expression #f)
      #:context #'make-sequence
      #:literals (let-values quote)
-     [(let-values ([_ (m-s '(_) '())]) . _)
-      #'m-s])
+     [(let-values ([_ (m-s '(_) '())]) . _) #'m-s])
    (-poly (a b)
           (let ([seq-vals
                  (lambda (a)
diff --git a/collects/typed-scheme/core.rkt b/collects/typed-scheme/core.rkt
index fefdf970..c8c25175 100644
--- a/collects/typed-scheme/core.rkt
+++ b/collects/typed-scheme/core.rkt
@@ -11,7 +11,7 @@
          (env type-name-env type-alias-env)
          (r:infer infer)
          (rep type-rep)
-         (except-in (utils utils tc-utils) infer)
+         (except-in (utils utils tc-utils arm) infer)
          (only-in (r:infer infer-dummy) infer-param)
          "tc-setup.rkt")
 
@@ -40,7 +40,7 @@
             [(optimized-body ...) (maybe-optimize #'transformed-body)])
            ;; reconstruct the module with the extra code
            ;; use the regular %#module-begin from `racket/base' for top-level printing
-           #`(#%module-begin optimized-body ... #,after-code check-syntax-help)))))]))
+           (arm #`(#%module-begin optimized-body ... #,after-code check-syntax-help))))))]))
 
 (define (ti-core stx)
   (syntax-parse stx
@@ -53,7 +53,7 @@
        ([optimized-body (car (maybe-optimize #`(#,body2)))])
        (syntax-parse body2
          ;; any of these do not produce an expression to be printed
-         [(head:invis-kw . _) #'optimized-body]
+         [(head:invis-kw . _) (arm #'optimized-body)]
          [_ (let ([ty-str (match type
                             ;; don't print results of type void
                             [(tc-result1: (== -Void type-equal?)) #f]
@@ -64,5 +64,5 @@
                             [x (int-err "bad type result: ~a" x)])])
               (if ty-str
                   #`(let ([type '#,ty-str])
-                      (begin0 optimized-body (display type)))
-                  #'optimized-body))])))]))
+                      (begin0 #,(arm #'optimized-body) (display type)))
+                  (arm #'optimized-body)))])))]))
diff --git a/collects/typed-scheme/optimizer/optimizer.rkt b/collects/typed-scheme/optimizer/optimizer.rkt
index 9f412703..0011c30b 100644
--- a/collects/typed-scheme/optimizer/optimizer.rkt
+++ b/collects/typed-scheme/optimizer/optimizer.rkt
@@ -14,7 +14,7 @@
 (define-syntax-class opt-expr
   #:commit
   (pattern e:opt-expr*
-           #:with opt (syntax-recertify #'e.opt this-syntax (current-code-inspector) #f)))
+           #:with opt #'e.opt))
 
 (define-syntax-class opt-expr*
   #:commit
diff --git a/collects/typed-scheme/tc-setup.rkt b/collects/typed-scheme/tc-setup.rkt
index 87ce15f0..0d4beec1 100644
--- a/collects/typed-scheme/tc-setup.rkt
+++ b/collects/typed-scheme/tc-setup.rkt
@@ -11,7 +11,7 @@
          (typecheck typechecker provide-handling tc-toplevel)
          (env tvar-env type-name-env type-alias-env)
          (r:infer infer)
-         (utils tc-utils)
+         (utils tc-utils disarm)
          (rep type-rep)
          (except-in (utils utils) infer)
          (only-in (r:infer infer-dummy) infer-param)
@@ -59,7 +59,7 @@
                      ;; reinitialize seen type variables
                      [type-name-references null])
         (do-time "Initialized Envs")
-        (let ([fully-expanded-stx (local-expand stx expand-ctxt null)])
+        (let ([fully-expanded-stx (disarm* (local-expand stx expand-ctxt null))])
           (when (show-input?)
             (pretty-print (syntax->datum fully-expanded-stx)))
           (do-time "Local Expand Done")
@@ -69,4 +69,4 @@
                          [debugging? #f])
             (let ([result (checker fully-expanded-stx)])
               (do-time "Typechecking Done")
-              . body)))))))
+              (let () . body))))))))
diff --git a/collects/typed-scheme/typecheck/tc-expr-unit.rkt b/collects/typed-scheme/typecheck/tc-expr-unit.rkt
index ff1cb31b..bdb582db 100644
--- a/collects/typed-scheme/typecheck/tc-expr-unit.rkt
+++ b/collects/typed-scheme/typecheck/tc-expr-unit.rkt
@@ -409,7 +409,9 @@
        (begin (tc-exprs (syntax->list #'es))
               (tc-expr #'e))]
       ;; other
-      [_ (tc-error/expr #:return (ret (Un)) "cannot typecheck unknown form : ~a\n" (syntax->datum form))]))
+      [_ 
+       (printf "~s\n" (continuation-mark-set->context (current-continuation-marks)))
+       (tc-error/expr #:return (ret (Un)) "cannot typecheck unknown form : ~a\n" (syntax->datum form))]))
 
   (parameterize ([current-orig-stx form])
     ;(printf "form: ~a\n" (syntax->datum form))
diff --git a/collects/typed-scheme/typecheck/tc-toplevel.rkt b/collects/typed-scheme/typecheck/tc-toplevel.rkt
index 4d0e25f4..84a0f982 100644
--- a/collects/typed-scheme/typecheck/tc-toplevel.rkt
+++ b/collects/typed-scheme/typecheck/tc-toplevel.rkt
@@ -50,7 +50,7 @@
       #:literals (values define-type-alias-internal define-typed-struct-internal define-type-internal
 			 define-typed-struct/exec-internal :-internal assert-predicate-internal
 			 require/typed-internal declare-refinement-internal
-			 define-values quote-syntax #%plain-app begin)
+			 define-values quote-syntax #%plain-app begin define-syntaxes)
       ;#:literal-sets (kernel-literals)
 
       ;; forms that are handled in other ways
@@ -157,7 +157,7 @@
       ;; define-syntaxes just get noted
       [(define-syntaxes (var:id ...) . rest)
        (map make-def-stx-binding (syntax->list #'(var ...)))]
-
+      
       ;; otherwise, do nothing in this pass
       ;; handles expressions, provides, requires, etc and whatnot
       [_ (list)])))
diff --git a/collects/typed-scheme/utils/arm.rkt b/collects/typed-scheme/utils/arm.rkt
new file mode 100644
index 00000000..d044e569
--- /dev/null
+++ b/collects/typed-scheme/utils/arm.rkt
@@ -0,0 +1,25 @@
+#lang racket/base
+(require (for-template racket/base))
+
+(provide arm)
+
+;; For simplicity, protect everything produced by Typed Racket.
+(define (arm stx)
+  (syntax-case stx (module #%plain-module-begin
+                       #%require #%provide begin 
+                       define-values define-syntaxes
+                       define-values-for-syntax)
+    [(module name initial-import mb)
+     (quasisyntax/loc stx (module name initial-import #,(arm #'mb)))]
+    [(#%plain-module-begin . _) (syntax-arm stx)]
+    [(#%require . _) stx]
+    [(#%provide . _) stx]
+    [(begin form ...)
+     (quasisyntax/loc stx (begin #,@(map arm (syntax->list #'(form ...)))))]
+    [(define-values ids expr)
+     (quasisyntax/loc stx (define-values ids #,(arm #'expr)))]
+    [(define-syntaxes ids expr)
+     (quasisyntax/loc stx (define-syntaxes ids #,(arm #'expr)))]
+    [(define-values-for-syntax ids expr) 
+     (quasisyntax/loc stx (define-values-for-syntax ids #,(arm #'expr)))]
+    [_ (syntax-arm stx)]))
diff --git a/collects/typed-scheme/utils/disarm.rkt b/collects/typed-scheme/utils/disarm.rkt
new file mode 100644
index 00000000..3e31384c
--- /dev/null
+++ b/collects/typed-scheme/utils/disarm.rkt
@@ -0,0 +1,26 @@
+#lang racket/base
+
+(provide disarm*)
+
+;; Typed Racket runs after macro expansion, and it must be priviledged,
+;; so it can just disarm all taints (and arm everything afterward).
+
+(define (disarm* stx)
+  (let loop ([v stx])
+    (cond
+     [(syntax? v)
+      (let* ([stx (syntax-disarm v orig-insp)]
+             [r (loop (syntax-e stx))])
+        (if (eq? r (syntax-e stx))
+            stx
+            (datum->syntax stx r stx stx)))]
+     [(pair? v) (let ([a (loop (car v))]
+                      [d (loop (cdr v))])
+                  (if (and (eq? a (car v))
+                           (eq? d (cdr v)))
+                      v
+                      (cons a d)))]
+     [else v])))
+
+(define orig-insp (current-code-inspector))
+
diff --git a/collects/typed/private/rewriter.rkt b/collects/typed/private/rewriter.rkt
index 45c29a5c..95e5f187 100644
--- a/collects/typed/private/rewriter.rkt
+++ b/collects/typed/private/rewriter.rkt
@@ -2,10 +2,11 @@
 (require (for-syntax syntax/parse racket/base syntax/id-table racket/dict
                      unstable/debug))
 
+(define-for-syntax code-insp (current-code-inspector))
+
 (define-for-syntax (rewrite stx tbl from)
   (define (rw stx) 
-    (syntax-recertify 
-     (syntax-parse stx #:literal-sets (kernel-literals)
+     (syntax-parse (syntax-disarm stx code-insp) #:literal-sets (kernel-literals)
        [i:identifier
         (dict-ref tbl #'i #'i)]
        ;; no expressions here
@@ -34,10 +35,7 @@
                (~or if begin begin0 set! #%plain-app #%expression
                     #%variable-reference with-continuation-mark))
          expr ...)
-        (quasisyntax/loc stx (#,#'kw #,@(map rw (syntax->list #'(expr ...)))))])
-     stx
-     (current-code-inspector)
-     #f))
+        (quasisyntax/loc stx (#,#'kw #,@(map rw (syntax->list #'(expr ...)))))]))
   (rw stx))
 
 (define-syntax (define-rewriter stx)