diff --git a/src/test/bench/shootout-fasta-redux.rs b/src/test/bench/shootout-fasta-redux.rs
index 5cb04fcd27a8f..35b5eab8a28ca 100644
--- a/src/test/bench/shootout-fasta-redux.rs
+++ b/src/test/bench/shootout-fasta-redux.rs
@@ -1,3 +1,5 @@
+// xfail-test FIXME #5985 Doesn't typecheck on x86
+
 use core::cast::transmute;
 use core::from_str::FromStr;
 use core::libc::{FILE, STDOUT_FILENO, c_int, fdopen, fputc, fputs, fwrite};
diff --git a/src/test/bench/shootout-threadring.rs b/src/test/bench/shootout-threadring.rs
index 9eb8a29cec030..213c5140ccf0c 100644
--- a/src/test/bench/shootout-threadring.rs
+++ b/src/test/bench/shootout-threadring.rs
@@ -10,6 +10,8 @@
 
 // Based on threadring.erlang by Jira Isa
 
+// xfail-test FIXME #5985 OOM's on the mac bot
+
 fn start(n_tasks: int, token: int) {
     let mut (p, ch1) = comm::stream();
     ch1.send(token);