diff --git a/haskell-decl-scan.el b/haskell-decl-scan.el
index e989c8b13..276a8f55d 100644
--- a/haskell-decl-scan.el
+++ b/haskell-decl-scan.el
@@ -217,6 +217,10 @@ only for `imenu' support.")
   (concat literate-haskell-ds-line-prefix haskell-ds-start-decl-re)
   "The regexp that starts a Bird-style literate Haskell declaration.")
 
+(defun haskell-ds-whitespace-p (char)
+  "Test if CHAR is a whitespace character."
+  (member char '(?\t ?\n ?\ )))
+
 (defun haskell-ds-move-to-decl (direction bird-literate fix)
   "General function for moving to the start of a declaration,
 either forwards or backwards from point, with normal or with Bird-style
@@ -360,7 +364,7 @@ there."
   ;; ensure result is `t' or `nil' instead of just truthy
   (if (or
        ;; is cursor on whitespace
-       (member (following-char) '(?\t ?\n ?\ ))
+       (haskell-ds-whitespace-p (following-char))
        ;; http://emacs.stackexchange.com/questions/14269/how-to-detect-if-the-point-is-within-a-comment-area
        ;; is cursor at begging, inside, or end of comment
        (let ((fontfaces (get-text-property (or pt