diff --git a/collects/racket/file.rkt b/collects/racket/file.rkt
index 6614cb8a1f..6a768e6704 100644
--- a/collects/racket/file.rkt
+++ b/collects/racket/file.rkt
@@ -354,23 +354,33 @@
                                      #f))))))])
         (let ([prefs (with-pref-params
                       (lambda ()
-                        (if use-lock? 
-                            (call-with-preference-file-lock
-                             'get-preference
-                             'shared
-                             (lambda ()
-                               (make-lock-file-name pref-file))
-                             (lambda ()
-                               (with-input-from-file pref-file read))
-                             lock-there)
-                            (with-input-from-file pref-file read))))])
+                        (with-handlers ([exn:fail:read? (lambda (exn)
+                                                          (log-error 
+                                                           (format "error reading preferences: ~a"
+                                                                   (exn-message exn)))
+                                                          null)])
+                          (if use-lock? 
+                              (call-with-preference-file-lock
+                               'get-preference
+                               'shared
+                               (lambda ()
+                                 (make-lock-file-name pref-file))
+                               (lambda ()
+                                 (with-input-from-file pref-file read))
+                               lock-there)
+                              (with-input-from-file pref-file read)))))])
           ;; Make sure file content had the right shape:
           (if (and (list? prefs)
                    (andmap (lambda (x)
-                             (and (pair? x) (pair? (cdr x)) (null? (cddr x))))
+                             (and (pair? x) 
+                                  (symbol? (car x))
+                                  (pair? (cdr x)) 
+                                  (null? (cddr x))))
                            prefs))
               prefs
-              null)))))
+              (begin
+                (log-error "preference file content is not a list of symbol--value lists")
+                null))))))
   (let* ([fn (path->complete-path
               (or filename
                   (find-system-path 'pref-file)))]
diff --git a/collects/scribblings/reference/filesystem.scrbl b/collects/scribblings/reference/filesystem.scrbl
index ecf9e5572c..4c8e941ed0 100644
--- a/collects/scribblings/reference/filesystem.scrbl
+++ b/collects/scribblings/reference/filesystem.scrbl
@@ -937,11 +937,13 @@ read an @elemref["old-prefs"]{old preferences file}, and then a
 collection, instead. If none of those files exists, the preference set
 is empty.
 
-The preference file should contain a symbol-keyed association list
-(written to the file with the default parameter settings).  Keys
+The preference file should contain a list of symbol--value lists
+written with the default parameter settings.  Keys
 starting with @racket[racket:], @racket[mzscheme:], @racket[mred:],
 and @racket[plt:] in any letter case are reserved for use by Racket
-implementers.
+implementers. If the preference file does not contain a list
+of symbol--value lists, an error is logged via @racket[log-error]
+and @racket[failure-thunk] is called.
 
 The result of @racket[get-preference] is the value associated with
 @racket[name] if it exists in the association list, or the result of