diff --git a/Cargo.toml b/Cargo.toml
index fe2658b37..254bad04a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -26,7 +26,7 @@ docopt = "0.8.1"
 env_logger = "0.4"
 failure = "0.1.1"
 filetime = "0.1"
-flate2 = "0.2"
+flate2 = "1.0"
 fs2 = "0.4"
 git2 = "0.6"
 git2-curl = "0.7"
diff --git a/src/cargo/ops/cargo_package.rs b/src/cargo/ops/cargo_package.rs
index 84a20c641..b72793ae6 100644
--- a/src/cargo/ops/cargo_package.rs
+++ b/src/cargo/ops/cargo_package.rs
@@ -196,7 +196,7 @@ fn tar(ws: &Workspace,
     // Prepare the encoder and its header
     let filename = Path::new(filename);
     let encoder = GzBuilder::new().filename(util::path2bytes(filename)?)
-                                  .write(dst, Compression::Best);
+                                  .write(dst, Compression::best());
 
     // Put all package files into a compressed archive
     let mut ar = Builder::new(encoder);
@@ -282,7 +282,7 @@ fn run_verify(ws: &Workspace, tar: &FileLock, opts: &PackageOpts) -> CargoResult
 
     config.shell().status("Verifying", pkg)?;
 
-    let f = GzDecoder::new(tar.file())?;
+    let f = GzDecoder::new(tar.file());
     let dst = tar.parent().join(&format!("{}-{}", pkg.name(), pkg.version()));
     if fs::metadata(&dst).is_ok() {
         fs::remove_dir_all(&dst)?;
diff --git a/src/cargo/sources/registry/mod.rs b/src/cargo/sources/registry/mod.rs
index 27984aa6c..16269a11d 100644
--- a/src/cargo/sources/registry/mod.rs
+++ b/src/cargo/sources/registry/mod.rs
@@ -323,7 +323,7 @@ impl<'cfg> RegistrySource<'cfg> {
             return Ok(dst)
         }
 
-        let gz = GzDecoder::new(tarball.file())?;
+        let gz = GzDecoder::new(tarball.file());
         let mut tar = Archive::new(gz);
         let prefix = dst.file_name().unwrap();
         let parent = dst.parent().unwrap();
diff --git a/tests/cross-publish.rs b/tests/cross-publish.rs
index 4dd0c292a..b971d45a8 100644
--- a/tests/cross-publish.rs
+++ b/tests/cross-publish.rs
@@ -47,7 +47,7 @@ fn simple_cross_package() {
 
     // Check that the tarball contains the files
     let f = File::open(&p.root().join("target/package/foo-0.0.0.crate")).unwrap();
-    let mut rdr = GzDecoder::new(f).unwrap();
+    let mut rdr = GzDecoder::new(f);
     let mut contents = Vec::new();
     rdr.read_to_end(&mut contents).unwrap();
     let mut ar = Archive::new(&contents[..]);
diff --git a/tests/package.rs b/tests/package.rs
index 42a491ebf..6ba37e984 100644
--- a/tests/package.rs
+++ b/tests/package.rs
@@ -54,7 +54,7 @@ src[/]main.rs
                 execs().with_status(0).with_stdout(""));
 
     let f = File::open(&p.root().join("target/package/foo-0.0.1.crate")).unwrap();
-    let mut rdr = GzDecoder::new(f).unwrap();
+    let mut rdr = GzDecoder::new(f);
     let mut contents = Vec::new();
     rdr.read_to_end(&mut contents).unwrap();
     let mut ar = Archive::new(&contents[..]);
@@ -531,7 +531,7 @@ src[..]main.rs
                 execs().with_status(0).with_stdout(""));
 
     let f = File::open(&p.root().join("target/package/nested-0.0.1.crate")).unwrap();
-    let mut rdr = GzDecoder::new(f).unwrap();
+    let mut rdr = GzDecoder::new(f);
     let mut contents = Vec::new();
     rdr.read_to_end(&mut contents).unwrap();
     let mut ar = Archive::new(&contents[..]);
@@ -617,7 +617,7 @@ See [..]
 
     // Check that the tarball contains the added file
     let f = File::open(&p.root().join("target/package/foo-0.0.1.crate")).unwrap();
-    let mut rdr = GzDecoder::new(f).unwrap();
+    let mut rdr = GzDecoder::new(f);
     let mut contents = Vec::new();
     rdr.read_to_end(&mut contents).unwrap();
     let mut ar = Archive::new(&contents[..]);
@@ -748,7 +748,7 @@ fn generated_manifest() {
                 execs().with_status(0));
 
     let f = File::open(&p.root().join("target/package/foo-0.0.1.crate")).unwrap();
-    let mut rdr = GzDecoder::new(f).unwrap();
+    let mut rdr = GzDecoder::new(f);
     let mut contents = Vec::new();
     rdr.read_to_end(&mut contents).unwrap();
     let mut ar = Archive::new(&contents[..]);
@@ -827,7 +827,7 @@ fn ignore_workspace_specifier() {
                 execs().with_status(0));
 
     let f = File::open(&p.root().join("target/package/bar-0.1.0.crate")).unwrap();
-    let mut rdr = GzDecoder::new(f).unwrap();
+    let mut rdr = GzDecoder::new(f);
     let mut contents = Vec::new();
     rdr.read_to_end(&mut contents).unwrap();
     let mut ar = Archive::new(&contents[..]);
diff --git a/tests/publish.rs b/tests/publish.rs
index d4af2e99a..ac12aa8d3 100644
--- a/tests/publish.rs
+++ b/tests/publish.rs
@@ -54,8 +54,8 @@ See [..]
     f.seek(SeekFrom::Current(sz as i64 + 4)).unwrap();
 
     // Verify the tarball
-    let mut rdr = GzDecoder::new(f).unwrap();
-    assert_eq!(rdr.header().filename().unwrap(), b"foo-0.0.1.crate");
+    let mut rdr = GzDecoder::new(f);
+    assert_eq!(rdr.header().unwrap().filename().unwrap(), b"foo-0.0.1.crate");
     let mut contents = Vec::new();
     rdr.read_to_end(&mut contents).unwrap();
     let mut ar = Archive::new(&contents[..]);
@@ -121,8 +121,8 @@ See [..]
     f.seek(SeekFrom::Current(sz as i64 + 4)).unwrap();
 
     // Verify the tarball
-    let mut rdr = GzDecoder::new(f).unwrap();
-    assert_eq!(rdr.header().filename().unwrap(), "foo-0.0.1.crate".as_bytes());
+    let mut rdr = GzDecoder::new(f);
+    assert_eq!(rdr.header().unwrap().filename().unwrap(), "foo-0.0.1.crate".as_bytes());
     let mut contents = Vec::new();
     rdr.read_to_end(&mut contents).unwrap();
     let mut ar = Archive::new(&contents[..]);
@@ -189,8 +189,8 @@ See [..]
     f.seek(SeekFrom::Current(sz as i64 + 4)).unwrap();
 
     // Verify the tarball
-    let mut rdr = GzDecoder::new(f).unwrap();
-    assert_eq!(rdr.header().filename().unwrap(), "foo-0.0.1.crate".as_bytes());
+    let mut rdr = GzDecoder::new(f);
+    assert_eq!(rdr.header().unwrap().filename().unwrap(), "foo-0.0.1.crate".as_bytes());
     let mut contents = Vec::new();
     rdr.read_to_end(&mut contents).unwrap();
     let mut ar = Archive::new(&contents[..]);