diff --git a/collects/typed-scheme/infer/constraints.rkt b/collects/typed-scheme/infer/constraints.rkt
index d4969197..e87137c0 100644
--- a/collects/typed-scheme/infer/constraints.rkt
+++ b/collects/typed-scheme/infer/constraints.rkt
@@ -75,7 +75,7 @@
                           [(map2 dmap2) (in-pairs maps2)])
                          (with-handlers ([exn:infer? (lambda (_) #f)])
                            (cons 
-                            (hash-union map1 map2 (lambda (k v1 v2) (c-meet v1 v2)))
+                            (simple-hash-union map1 map2 (lambda (k v1 v2) (c-meet v1 v2)))
                             (dmap-meet dmap1 dmap2)))))])
       (when (null? maps)
         (fail! maps1 maps2))
diff --git a/collects/typed-scheme/infer/dmap.rkt b/collects/typed-scheme/infer/dmap.rkt
index c8857c91..1735c49c 100644
--- a/collects/typed-scheme/infer/dmap.rkt
+++ b/collects/typed-scheme/infer/dmap.rkt
@@ -62,5 +62,5 @@
 
 (define (dmap-meet dm1 dm2)
   (make-dmap
-   (hash-union (dmap-map dm1) (dmap-map dm2)
-               (lambda (k dc1 dc2) (dcon-meet dc1 dc2)))))
+   (simple-hash-union (dmap-map dm1) (dmap-map dm2)
+                      (lambda (k dc1 dc2) (dcon-meet dc1 dc2)))))
diff --git a/collects/typed-scheme/utils/tc-utils.rkt b/collects/typed-scheme/utils/tc-utils.rkt
index cc8cc926..cea09441 100644
--- a/collects/typed-scheme/utils/tc-utils.rkt
+++ b/collects/typed-scheme/utils/tc-utils.rkt
@@ -47,7 +47,7 @@ don't depend on any other portion of the system
     (when (and (warn-unreachable?)
                (log-level? l 'warning)
                (and (syntax-transforming?) (syntax-original? (syntax-local-introduce e)))
-               #;(and (orig-module-stx) (eq? (debug syntax-source-module e) (debug syntax-source-module (orig-module-stx))))
+               #;(and (orig-module-stx) (eq? (debug/call syntax-source-module e) (debug/call syntax-source-module (orig-module-stx))))
 	       #;(syntax-source-module stx))
       (log-message l 'warning (format "Typed Scheme has detected unreachable code: ~e" (syntax->datum (locate-stx e)))
                    e))))