1 files changed, 3 insertions, 0 deletions
diff --git a/src/io.c b/src/io.c
index 51a659f0e..452a61a3f 100644
--- a/src/io.c
+++ b/src/io.c
@@ -705,6 +705,9 @@ mrb_io_syswrite(mrb_state *mrb, mrb_value io)
     fd = fptr->fd2;
   }
   length = write(fd, RSTRING_PTR(buf), RSTRING_LEN(buf));
+  if (length == -1) {
+    mrb_sys_fail(mrb, 0);
+  }
 
   return mrb_fixnum_value(length);
 }