diff --git a/read.scm b/read.scm
index 66b3962..1007c00 100644
--- a/read.scm
+++ b/read.scm
@@ -676,7 +676,8 @@
 (define readtable:hash
   (readtable:process
    (readtable:empty/default read:read-hash-messages)
-   ;; TODO: add whitespace to fail
+   (list readtable:update-list readtable:ASCII-whitespace
+         (readtable:error 'hash 'whitespace-after-hash))
    (list readtable:update #\| (readtable:jump/next readtable:block-comment))
    (list readtable:update #\; readtable:datum-comment)
    (list readtable:update #\\ readtable:character)
@@ -697,9 +698,7 @@
   (lambda ()
     (readtable:process
      (readtable:empty/default readtable:read-ident)
-     (list readtable:update-list
-           readtable:ASCII-whitespace
-           readtable:skip)
+     (list readtable:update-list readtable:ASCII-whitespace readtable:skip)
      (list readtable:update #f (readtable:return 'eof))
      (list readtable:update %bol readtable:read-list)
      (list readtable:update %eol (readtable:error 'top "unbalanced list"))
@@ -794,3 +793,4 @@
 (read-all "#!fold-case #TRUE")
 (read-all "#u8(x y z w)")
 (read-all "#\\newline")
+(read-all "#\\a")