diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index f22f8ac8efc7..4a76e2aaa164 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -56,29 +56,29 @@ static WHITELIST_CRATES: &'static [CrateVersion] = &[
 
 /// Whitelist of crates rustc is allowed to depend on. Avoid adding to the list if possible.
 static WHITELIST: &'static [Crate] = &[
-//    Crate("backtrace"),
-//    Crate("backtrace-sys"),
-//    Crate("bitflags"),
-//    Crate("byteorder"),
-//    Crate("cc"),
-//    Crate("cfg-if"),
-//    Crate("flate2"),
-//    Crate("fuchsia-zircon"),
-//    Crate("fuchsia-zircon-sys"),
-//    Crate("jobserver"),
-//    Crate("lazy_static"),
-//    Crate("libc"),
-//    Crate("log"),
-//    Crate("miniz-sys"),
-//    Crate("num_cpus"),
-//    Crate("rand"),
-//    Crate("rustc"),
-//    Crate("rustc-demangle"),
-//    Crate("rustc_trans"),
-//    Crate("tempdir"),
-//    Crate("winapi"),
-//    Crate("winapi-i686-pc-windows-gnu"),
-//    Crate("winapi-x86_64-pc-windows-gnu"),
+    Crate("backtrace"),
+    Crate("backtrace-sys"),
+    Crate("bitflags"),
+    Crate("byteorder"),
+    Crate("cc"),
+    Crate("cfg-if"),
+    Crate("flate2"),
+    Crate("fuchsia-zircon"),
+    Crate("fuchsia-zircon-sys"),
+    Crate("jobserver"),
+    Crate("lazy_static"),
+    Crate("libc"),
+    Crate("log"),
+    Crate("miniz-sys"),
+    Crate("num_cpus"),
+    Crate("rand"),
+    Crate("rustc"),
+    Crate("rustc-demangle"),
+    Crate("rustc_trans"),
+    Crate("tempdir"),
+    Crate("winapi"),
+    Crate("winapi-i686-pc-windows-gnu"),
+    Crate("winapi-x86_64-pc-windows-gnu"),
 ];
 
 // Some types for Serde to deserialize the output of `cargo metadata` to...