diff --git a/Cargo.toml b/Cargo.toml
index 82a2e71bb2b..b572aebdbbe 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -58,4 +58,3 @@ rustc_tools_util = { version = "0.2.0", path = "rustc_tools_util"}
 
 [features]
 deny-warnings = []
-debugging = []
diff --git a/appveyor.yml b/appveyor.yml
index 075c519cd4b..bf6133e98a0 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -37,10 +37,10 @@ install:
 build: false
 
 build_script:
-  - cargo build --features debugging
+  - cargo build --features deny-warnings
 
 test_script:
-  - cargo test --features debugging
+  - cargo test --features deny-warnings
 
 notifications:
   - provider: Email
diff --git a/ci/base-tests.sh b/ci/base-tests.sh
index 4a64b19d80a..d3fd262b600 100755
--- a/ci/base-tests.sh
+++ b/ci/base-tests.sh
@@ -12,12 +12,12 @@ if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then
   remark -f ./*.md -f doc/*.md > /dev/null
 fi
 # build clippy in debug mode and run tests
-cargo build --features "debugging deny-warnings"
-cargo test --features "debugging deny-warnings"
+cargo build --features deny-warnings
+cargo test --features deny-warnings
 
-(cd clippy_lints && cargo test)
-(cd rustc_tools_util && cargo test)
-(cd clippy_dev && cargo test)
+(cd clippy_lints && cargo test --features deny-warnings)
+(cd rustc_tools_util && cargo test --features deny-warnings)
+(cd clippy_dev && cargo test --features deny-warnings)
 
 # make sure clippy can be called via ./path/to/cargo-clippy
 (
diff --git a/clippy_dev/Cargo.toml b/clippy_dev/Cargo.toml
index e2e946d06f2..b30ba61d299 100644
--- a/clippy_dev/Cargo.toml
+++ b/clippy_dev/Cargo.toml
@@ -11,3 +11,6 @@ regex = "1"
 lazy_static = "1.0"
 shell-escape = "0.1"
 walkdir = "2"
+
+[features]
+deny-warnings = []
diff --git a/clippy_dev/src/lib.rs b/clippy_dev/src/lib.rs
index 327774ea0f2..f73e7b86720 100644
--- a/clippy_dev/src/lib.rs
+++ b/clippy_dev/src/lib.rs
@@ -1,3 +1,5 @@
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+
 use itertools::Itertools;
 use lazy_static::lazy_static;
 use regex::Regex;
diff --git a/clippy_dev/src/main.rs b/clippy_dev/src/main.rs
index 9c9d3eae588..3010e0d2489 100644
--- a/clippy_dev/src/main.rs
+++ b/clippy_dev/src/main.rs
@@ -1,3 +1,5 @@
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+
 extern crate clap;
 extern crate clippy_dev;
 extern crate regex;
diff --git a/clippy_lints/Cargo.toml b/clippy_lints/Cargo.toml
index 608fb668c5a..dae403cbb4f 100644
--- a/clippy_lints/Cargo.toml
+++ b/clippy_lints/Cargo.toml
@@ -35,4 +35,4 @@ semver = "0.9.0"
 url = { version =  "2.1.0", features = ["serde"] }
 
 [features]
-debugging = []
+deny-warnings = []
diff --git a/rustc_tools_util/Cargo.toml b/rustc_tools_util/Cargo.toml
index 5d37f935375..6f0fc5bee8f 100644
--- a/rustc_tools_util/Cargo.toml
+++ b/rustc_tools_util/Cargo.toml
@@ -9,4 +9,8 @@ license = "MIT OR Apache-2.0"
 keywords = ["rustc", "tool", "git", "version", "hash"]
 categories = ["development-tools"]
 edition = "2018"
+
 [dependencies]
+
+[features]
+deny-warnings = []
diff --git a/rustc_tools_util/src/lib.rs b/rustc_tools_util/src/lib.rs
index 36b58a398dc..ff2a7de5725 100644
--- a/rustc_tools_util/src/lib.rs
+++ b/rustc_tools_util/src/lib.rs
@@ -1,3 +1,5 @@
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+
 use std::env;
 
 #[macro_export]