1 files changed, 1 insertions, 1 deletions
diff --git a/rubyio.h b/rubyio.h
index 81f162a012..f4b72781e5 100644
--- a/rubyio.h
+++ b/rubyio.h
@@ -54,7 +54,7 @@ int  rb_io_mode_flags _((const char*));
 void rb_io_check_writable _((OpenFile*));
 void rb_io_check_readable _((OpenFile*));
 void rb_io_fptr_finalize _((OpenFile*));
-void rb_io_unbuffered _((OpenFile*));
+void rb_io_synchronized _((OpenFile*));
 void rb_io_check_closed _((OpenFile*));
 void rb_eof_error _((void));