diff --git a/.circleci/config.yml b/.circleci/config.yml
index 0f118da..069c56d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -40,4 +40,4 @@ jobs:
           command: rustup component add clippy
       - run:
           name: Run cargo clippy
-          command: cargo clippy -- -Drust-2018-idioms
+          command: cargo clippy -- -Drust-2018-idioms -Dwarnings