diff --git a/src/test/run-pass/issue-3168.rs b/src/test/run-pass/issue-3168.rs
index 421813962e49..0da0ade08926 100644
--- a/src/test/run-pass/issue-3168.rs
+++ b/src/test/run-pass/issue-3168.rs
@@ -1,3 +1,5 @@
+// xfail-fast
+
 fn main() {
     let (c,p) = pipes::stream();
     do task::try {
diff --git a/src/test/run-pass/issue-3176.rs b/src/test/run-pass/issue-3176.rs
index e89d6466135f..0172fff076fd 100644
--- a/src/test/run-pass/issue-3176.rs
+++ b/src/test/run-pass/issue-3176.rs
@@ -1,3 +1,5 @@
+// xfail-fast
+
 import pipes::{select2, selectable};
 
 fn main() {