diff --git a/collects/mzlib/port.rkt b/collects/mzlib/port.rkt
index 330f13f..fad66f2 100644
--- a/collects/mzlib/port.rkt
+++ b/collects/mzlib/port.rkt
@@ -529,8 +529,7 @@
           (lambda (n evt target-evt) (port-commit-peeked n evt target-evt p)))
      (lambda () (port-next-location p))
      (lambda () (port-count-lines! p))
-     (let-values ([(line col pos) (port-next-location p)])
-       (or pos (file-position p))))))
+     (add1 (file-position p)))))
 
 ;; Not kill-safe.
 (define make-pipe-with-specials
@@ -891,9 +890,14 @@
                  n)))))
        (lambda ()
          (when close-orig?
-           (close-input-port port)))))))
-
-
+           (close-input-port port)))
+       (and (port-provides-progress-evts? port)
+            (lambda () (port-progress-evt port)))
+       (and (port-provides-progress-evts? port)
+            (lambda (n evt target-evt) (port-commit-peeked n evt target-evt port)))
+       (lambda () (port-next-location port))
+       (lambda () (port-count-lines! port))
+       (add1 (file-position port))))))
 
 (define special-filter-input-port
   (lambda (p filter [close? #t])
@@ -927,8 +931,7 @@
           (lambda (n evt target-evt) (port-commit-peeked n evt target-evt p)))
      (lambda () (port-next-location p))
      (lambda () (port-count-lines! p))
-     (let-values ([(l c p) (port-next-location p)])
-       p))))
+     (add1 (file-position p)))))
 
 ;; ----------------------------------------
 
@@ -1758,8 +1761,7 @@
     (let ([new (transplant-output-port
                 p
                 (lambda () (port-next-location p))
-                (let-values ([(line col pos) (port-next-location p)])
-                  (or pos (file-position p)))
+                (add1 (file-position p))
                 close?
                 (lambda () (port-count-lines! p)))])
       (port-display-handler new (port-display-handler p))
@@ -1771,8 +1773,7 @@
     (let ([new (transplant-input-port
                 p
                 (lambda () (port-next-location p))
-                (let-values ([(line col pos) (port-next-location p)])
-                  (or pos (file-position p)))
+                (add1 (file-position p))
                 close?
                 (lambda () (port-count-lines! p)))])
       (port-read-handler new (port-read-handler p))