1 files changed, 1 insertions, 1 deletions
diff --git a/io.c b/io.c
index 1dba2ea69a..ae5634e25b 100644
--- a/io.c
+++ b/io.c
@@ -2627,7 +2627,7 @@ rb_io_ctl(io, req, arg, io_p)
     int io_p;
 {
 #if !defined(MSDOS) && !defined(__human68k__)
-    int cmd = NUM2INT(req);
+    int cmd = NUM2ULONG(req);
     OpenFile *fptr;
     int len = 0;
     int fd;