diff --git a/scheme/lib/ftp.scm b/scheme/lib/ftp.scm
index 55504ec..8abe4e9 100644
--- a/scheme/lib/ftp.scm
+++ b/scheme/lib/ftp.scm
@@ -206,9 +206,8 @@
 (define (ftp-size connection file)
   (let* ((reply (ftp-send-command connection
 				  (format #f "SIZE ~a" file))))
-    (and (string? reply)
-         (string->number (substring reply
-                                    4 (- (string-length reply) 1))))))
+    (string->number (substring reply
+			       4 (string-length reply)))))
 
 ;; Abort the current data transfer. Maybe we should close the data
 ;; socket?