diff --git a/src/Cargo.lock b/src/Cargo.lock
index 8729335faba81..f1c3f83761b89 100644
--- a/src/Cargo.lock
+++ b/src/Cargo.lock
@@ -1691,8 +1691,6 @@ dependencies = [
  "cfg-if 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "ena 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "parking_lot 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "parking_lot_core 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "serialize 0.0.0",
  "stable_deref_trait 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
diff --git a/src/ci/docker/x86_64-gnu-debug/Dockerfile b/src/ci/docker/x86_64-gnu-debug/Dockerfile
index ff6ab1013b4c2..95d41028595f8 100644
--- a/src/ci/docker/x86_64-gnu-debug/Dockerfile
+++ b/src/ci/docker/x86_64-gnu-debug/Dockerfile
@@ -16,7 +16,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
 
-ENV PARALLEL_CHECK 1
 ENV RUST_CONFIGURE_ARGS \
       --build=x86_64-unknown-linux-gnu \
       --enable-debug \
diff --git a/src/librustc_data_structures/Cargo.toml b/src/librustc_data_structures/Cargo.toml
index e1f0a74fc683d..7845296c8e139 100644
--- a/src/librustc_data_structures/Cargo.toml
+++ b/src/librustc_data_structures/Cargo.toml
@@ -14,8 +14,3 @@ log = "0.4"
 serialize = { path = "../libserialize" }
 cfg-if = "0.1.2"
 stable_deref_trait = "1.0.0"
-parking_lot_core = "0.2.8"
-
-[dependencies.parking_lot]
-version = "0.5"
-features = ["nightly"]
diff --git a/src/librustc_data_structures/lib.rs b/src/librustc_data_structures/lib.rs
index 622fb423b51e4..94407d8bbbfd7 100644
--- a/src/librustc_data_structures/lib.rs
+++ b/src/librustc_data_structures/lib.rs
@@ -45,7 +45,6 @@ extern crate log;
 extern crate serialize as rustc_serialize; // used by deriving
 #[cfg(unix)]
 extern crate libc;
-extern crate parking_lot;
 #[macro_use]
 extern crate cfg_if;
 extern crate stable_deref_trait;