1 files changed, 1 insertions, 0 deletions
diff --git a/rubyio.h b/rubyio.h
index 7130be7666..44f679494e 100644
--- a/rubyio.h
+++ b/rubyio.h
@@ -67,6 +67,7 @@ void rb_io_check_writable _((OpenFile*));
 void rb_io_check_readable _((OpenFile*));
 void rb_io_fptr_finalize _((OpenFile*));
 void rb_io_synchronized _((OpenFile*));
+void rb_io_check_initialized _((OpenFile*));
 void rb_io_check_closed _((OpenFile*));
 int rb_io_wait_readable _((int));
 int rb_io_wait_writable _((int));