diff --git a/scheme/ikarus.posix.ss b/scheme/ikarus.posix.ss
index 95f516b..991a9cd 100644
--- a/scheme/ikarus.posix.ss
+++ b/scheme/ikarus.posix.ss
@@ -291,19 +291,23 @@
   (define ($file-time x who proc)
     (unless (string? x) 
       (die who "not a string" x))
-    (let ([p (cons #f #f)])
-      (let ([v (proc (string->utf8 x) p)])
-        (case v
-          [(0) (+ (* (car p) #e1e9) (cdr p))]
-          [else (raise/strerror who v x)]))))
+    (let ([v (proc (string->utf8 x))])
+      (cond
+        [(bytevector? v) 
+         (let ([n0 (bytevector-u8-ref v 0)]
+               [n1 (bytevector-u8-ref v 1)])
+           (+ (* (bytevector-uint-ref v 2 (native-endianness) n0)
+                 #e1e9)
+              (bytevector-uint-ref v (+ 2 n0) (native-endianness) n1)))]
+        [else (raise/strerror who v x)])))
 
   (define (file-ctime x)
     ($file-time x 'file-ctime 
-      (lambda (u p) (foreign-call "ikrt_file_ctime" u p))))
+      (lambda (u) (foreign-call "ikrt_file_ctime2" u))))
 
   (define (file-mtime x)
     ($file-time x 'file-mtime 
-      (lambda (u p) (foreign-call "ikrt_file_mtime" u p))))
+      (lambda (u) (foreign-call "ikrt_file_mtime2" u))))
 
   (define ($getenv-bv key)
     (foreign-call "ikrt_getenv" key))
diff --git a/src/ikarus-io.c b/src/ikarus-io.c
index e8c2ccd..2abcac4 100644
--- a/src/ikarus-io.c
+++ b/src/ikarus-io.c
@@ -285,6 +285,41 @@ ikrt_shutdown(ikptr s /*, ikpcb* pcb*/){
 }
 
 
+static ikptr 
+timespec_bytevector(struct timespec* s, ikpcb* pcb) {
+  int len = sizeof(struct timespec);
+  ikptr r = ik_safe_alloc(pcb, align(disp_bytevector_data+len+3));
+  ref(r, 0) = fix(len+2);
+  *((char*)(r+disp_bytevector_data+0)) = sizeof(s->tv_sec);
+  *((char*)(r+disp_bytevector_data+1)) = sizeof(s->tv_nsec);
+  memcpy((char*)(r+disp_bytevector_data+2), s, len);
+  *((char*)(r+disp_bytevector_data+len+2)) = 0;
+  return r + bytevector_tag;
+}
+
+ikptr
+ikrt_file_ctime2(ikptr filename, ikpcb* pcb){
+  struct stat s;
+  int err = stat((char*)(filename + off_bytevector_data), &s);
+  if(err) {
+    return ik_errno_to_code();
+  }
+  return timespec_bytevector(&s.st_ctimespec, pcb);
+}
+
+ikptr
+ikrt_file_mtime2(ikptr filename, ikpcb* pcb){
+  struct stat s;
+  int err = stat((char*)(filename + off_bytevector_data), &s);
+  if(err) {
+    return ik_errno_to_code();
+  }
+  return timespec_bytevector(&s.st_mtimespec, pcb);
+}
+
+
+
+
 ikptr
 ikrt_file_ctime(ikptr filename, ikptr res){
   struct stat s;