diff --git a/collects/at-exp/lang/reader.ss b/collects/at-exp/lang/reader.ss
index 36f3680347..0c12b03a75 100644
--- a/collects/at-exp/lang/reader.ss
+++ b/collects/at-exp/lang/reader.ss
@@ -1,6 +1,6 @@
 #lang scheme/base
 
-;; FIXME: This code was largely cut-and-pasted from the planet reader. 
+;; FIXME: This code was largely cut-and-pasted from the planet reader.
 
 (require syntax/readerr
          (only-in scribble/reader make-at-readtable))
@@ -10,50 +10,42 @@
          get-info)
 
 (define (at-get in export-sym src line col pos mk-fail-thunk)
-  (let ([spec (regexp-try-match #px"^[ \t]+(.*?)(?=\\s|$)" in)]
-        [bad (lambda (str eof?)
-               ((if eof?
-                    raise-read-eof-error 
-                    raise-read-error)
-                (format "bad language path following at-exp~a~a"
-                        (if str ": " "")
-                        (or str ""))
-                src line col pos
-                (let-values ([(line col pos2) (port-next-location in)])
-                  (and pos pos2 (- pos2 pos)))))])
-    (if (or (not spec)
-            (equal? (cadr spec) ""))
-        (bad #f (eof-object? (peek-byte in)))
-        (let ([parsed-spec
-               (let ([s (string->symbol 
-                         (string-append (bytes->string/latin-1 (cadr spec))
-                                        "/lang/reader"))])
-                 (if (module-path? s)
-                     s
-                     #f))])
-          (if parsed-spec
-              (begin
-                ((current-reader-guard) parsed-spec)
-                (dynamic-require parsed-spec export-sym (mk-fail-thunk spec)))
-              (bad (cadr spec) #f))))))
+  (define (bad str eof?)
+    ((if eof? raise-read-eof-error raise-read-error)
+     (let ([msg "bad language path following at-exp"])
+       (if str (string-append msg ": " str) msg))
+     src line col pos
+     (let-values ([(line col pos2) (port-next-location in)])
+       (and pos pos2 (- pos2 pos)))))
+  (define spec (regexp-try-match #px"^[ \t]+(.*?)(?=\\s|$)" in))
+  (if (or (not spec) (equal? (cadr spec) ""))
+    (bad #f (eof-object? (peek-byte in)))
+    (let ([parsed-spec
+           (let ([s (string->symbol
+                     (string-append (bytes->string/latin-1 (cadr spec))
+                                    "/lang/reader"))])
+             (and (module-path? s) s))])
+      (if parsed-spec
+        (begin ((current-reader-guard) parsed-spec)
+               (dynamic-require parsed-spec export-sym (mk-fail-thunk spec)))
+        (bad (cadr spec) #f)))))
 
-(define (get-info in mod line col pos)
-  (at-get in 'get-info (object-name in) line col pos
-              (lambda (spec) (lambda () (lambda (tag) #f)))))
+(define (get-info inp mod line col pos)
+  (at-get inp 'get-info (object-name inp) line col pos
+          (lambda (spec) (lambda () (lambda (tag) #f)))))
 
 (define at-readtable (make-at-readtable))
 
 (define (at-read-fn in read-sym args src mod line col pos)
   (let ([r (at-get in read-sym src #|mod|# line col pos
-                   (lambda (spec) 
+                   (lambda (spec)
                      (lambda ()
-                       (error 'at "cannot find reader for `#lang at ~a'" spec))))])
+                       (error 'at-exp "cannot find reader for `#lang at ~a'"
+                              spec))))])
     (parameterize ([current-readtable at-readtable])
-      (if (and (procedure? r)
-               (procedure-arity-includes? r (+ 5 (length args))))
-          (apply r (append args
-                           (list in mod line col pos)))
-          (apply r (append args (list in)))))))
+      (if (and (procedure? r) (procedure-arity-includes? r (+ 5 (length args))))
+        (apply r (append args (list in mod line col pos)))
+        (apply r (append args (list in)))))))
 
 (define (at-read inp mod line col pos)
   (at-read-fn inp 'read null (object-name inp) mod line col pos))