better error message.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/io.c b/src/io.c
index e80483145..5a6079e99 100644
--- a/src/io.c
+++ b/src/io.c
@@ -437,7 +437,7 @@ mrb_io_sysread(mrb_state *mrb, mrb_value io)
       }
       break;
     case -1: /* Error */
-      mrb_raise(mrb, E_IO_ERROR, "sysread failed");
+      mrb_sys_fail(mrb, "sysread failed");
       break;
     default:
       if (RSTRING_LEN(buf) != ret) {