diff --git a/.circleci/config.yml b/.circleci/config.yml
index 18bb4665ad..77f01a79df 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -40,6 +40,9 @@ jobs:
     resource_class: medium
     steps:
       - run: cat ~/.profile >> $BASH_ENV
+      - run:
+          name: "Set RUSTFLAGS to fail the build if there are warnings"
+          command: echo 'export RUSTFLAGS="-D warnings"' >> $BASH_ENV
       - checkout
       - run: cargo test
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