2 files changed, 11 insertions, 5 deletions
diff --git a/compiler/rustc_serialize/tests/leb128.rs b/compiler/rustc_serialize/tests/leb128.rs
index dc9b32a968b..fafe4b91a95 100644
--- a/compiler/rustc_serialize/tests/leb128.rs
+++ b/compiler/rustc_serialize/tests/leb128.rs
@@ -1,4 +1,6 @@
 use rustc_serialize::leb128::*;
+use rustc_serialize::opaque::MemDecoder;
+use rustc_serialize::opaque::MAGIC_END_BYTES;
 use rustc_serialize::Decoder;
 
 macro_rules! impl_test_unsigned_leb128 {
@@ -25,13 +27,15 @@ macro_rules! impl_test_unsigned_leb128 {
                 let n = $write_fn_name(&mut buf, x);
                 stream.extend(&buf[..n]);
             }
+            let stream_end = stream.len();
+            stream.extend(MAGIC_END_BYTES);
 
-            let mut decoder = rustc_serialize::opaque::MemDecoder::new(&stream, 0);
+            let mut decoder = MemDecoder::new(&stream, 0).unwrap();
             for &expected in &values {
                 let actual = $read_fn_name(&mut decoder);
                 assert_eq!(expected, actual);
             }
-            assert_eq!(stream.len(), decoder.position());
+            assert_eq!(stream_end, decoder.position());
         }
     };
 }
@@ -72,13 +76,15 @@ macro_rules! impl_test_signed_leb128 {
                 let n = $write_fn_name(&mut buf, x);
                 stream.extend(&buf[..n]);
             }
+            let stream_end = stream.len();
+            stream.extend(MAGIC_END_BYTES);
 
-            let mut decoder = rustc_serialize::opaque::MemDecoder::new(&stream, 0);
+            let mut decoder = MemDecoder::new(&stream, 0).unwrap();
             for &expected in &values {
                 let actual = $read_fn_name(&mut decoder);
                 assert_eq!(expected, actual);
             }
-            assert_eq!(stream.len(), decoder.position());
+            assert_eq!(stream_end, decoder.position());
         }
     };
 }
diff --git a/compiler/rustc_serialize/tests/opaque.rs b/compiler/rustc_serialize/tests/opaque.rs
index 45ff85f38d2..833151d82be 100644
--- a/compiler/rustc_serialize/tests/opaque.rs
+++ b/compiler/rustc_serialize/tests/opaque.rs
@@ -42,7 +42,7 @@ fn check_round_trip<
     encoder.finish().unwrap();
 
     let data = fs::read(&tmpfile).unwrap();
-    let mut decoder = MemDecoder::new(&data[..], 0);
+    let mut decoder = MemDecoder::new(&data[..], 0).unwrap();
     for value in values {
         let decoded = Decodable::decode(&mut decoder);
         assert_eq!(value, decoded);