diff --git a/src/librustc_data_structures/stable_hasher.rs b/src/librustc_data_structures/stable_hasher.rs
index f3572d3e25b3..5e291ea3c152 100644
--- a/src/librustc_data_structures/stable_hasher.rs
+++ b/src/librustc_data_structures/stable_hasher.rs
@@ -81,7 +81,7 @@ impl StableHasherResult for [u8; 20] {
 impl StableHasherResult for u128 {
     fn finish(mut hasher: StableHasher<Self>) -> Self {
         let hash_bytes: &[u8] = hasher.finalize();
-        assert!(hash_bytes.len() >= mem::size_of::<u64>() * 2);
+        assert!(hash_bytes.len() >= mem::size_of::<u128>());
 
         unsafe {
             ::std::ptr::read_unaligned(hash_bytes.as_ptr() as *const u128)
diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs
index 8e04e47e25f9..7267f510a490 100644
--- a/src/libsyntax/codemap.rs
+++ b/src/libsyntax/codemap.rs
@@ -618,6 +618,7 @@ impl FilePathMapping {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use std::borrow::Cow;
     use std::rc::Rc;
 
     #[test]
@@ -627,12 +628,12 @@ mod tests {
                                 "first line.\nsecond line".to_string());
         fm.next_line(BytePos(0));
         // Test we can get lines with partial line info.
-        assert_eq!(fm.get_line(0), Some("first line."));
+        assert_eq!(fm.get_line(0), Some(Cow::from("first line.")));
         // TESTING BROKEN BEHAVIOR: line break declared before actual line break.
         fm.next_line(BytePos(10));
-        assert_eq!(fm.get_line(1), Some("."));
+        assert_eq!(fm.get_line(1), Some(Cow::from(".")));
         fm.next_line(BytePos(12));
-        assert_eq!(fm.get_line(2), Some("second line"));
+        assert_eq!(fm.get_line(2), Some(Cow::from("second line")));
     }
 
     #[test]