diff --git a/ice-9/boot-9.scm b/ice-9/boot-9.scm
index 0e098dd56..c2163fd38 100644
--- a/ice-9/boot-9.scm
+++ b/ice-9/boot-9.scm
@@ -544,8 +544,10 @@
 (define (tms:cutime obj) (vector-ref obj 3))
 (define (tms:cstime obj) (vector-ref obj 4))
 
-(define (file-position . args) (apply ftell args))
-(define (file-set-position . args) (apply fseek args))
+(define file-position ftell)
+(define (file-set-position port offset . whence)
+  (let ((whence (if (eq? whence '()) SEEK_SET (car whence))))
+    (seek port offset whence)))
 
 (define (move->fdes fd/port fd)
   (cond ((integer? fd/port)