Negative RBOOL usage

1 files changed, 1 insertions, 1 deletions

diff --git a/io.c b/io.c
index 3fab54e406..67d865650c 100644
--- a/io.c
+++ b/io.c
@@ -8933,7 +8933,7 @@ rb_io_autoclose_p(VALUE io)
 {
     rb_io_t *fptr = RFILE(io)->fptr;
     rb_io_check_closed(fptr);
-    return (fptr->mode & FMODE_PREP) ? Qfalse : Qtrue;
+    return RBOOL(!(fptr->mode & FMODE_PREP));
 }
 
 /*