1 files changed, 1 insertions, 0 deletions
diff --git a/io.c b/io.c
index fb822f0f58..17a2d30c71 100644
--- a/io.c
+++ b/io.c
@@ -10497,6 +10497,7 @@ rb_f_backquote(VALUE obj, VALUE str)
     if (NIL_P(port)) return rb_str_new(0,0);
 
     GetOpenFile(port, fptr);
+    rb_obj_hide(port);
     result = read_all(fptr, remain_size(fptr), Qnil);
     rb_io_close(port);
     RFILE(port)->fptr = NULL;