diff --git a/src/libcore/str.rs b/src/libcore/str.rs
index 9f40dd5c3a48..f93a5cb42557 100644
--- a/src/libcore/str.rs
+++ b/src/libcore/str.rs
@@ -1769,6 +1769,7 @@ mod tests {
 
     #[test]
     #[should_fail]
+    #[ignore(cfg(target_os = "win32"))]
     fn test_from_bytes_fail() {
         let bb = [0xff_u8, 0xb8_u8, 0xa8_u8,
                   0xe0_u8, 0xb9_u8, 0x84_u8,
@@ -1995,6 +1996,7 @@ mod tests {
 
     #[test]
     #[should_fail]
+    #[ignore(cfg(target_os = "win32"))]
     fn test_windowed_() {
         let _x = windowed(0u, "abcd");
     }
diff --git a/src/libcore/vec.rs b/src/libcore/vec.rs
index 357df699f877..6275f7159370 100644
--- a/src/libcore/vec.rs
+++ b/src/libcore/vec.rs
@@ -1526,6 +1526,7 @@ mod tests {
 
     #[test]
     #[should_fail]
+    #[ignore(cfg(target_os = "win32"))]
     fn test_windowed_() {
         let _x = windowed (0u, [1u,2u,3u,4u,5u,6u]);
     }