diff --git a/.azure/azure-pipelines.yml b/.azure/azure-pipelines.yml
index 4c160576b..54bbc5bb7 100644
--- a/.azure/azure-pipelines.yml
+++ b/.azure/azure-pipelines.yml
@@ -29,7 +29,7 @@ steps:
       rustc -Vv
       echo "##vso[task.prependpath]$HOME/.cargo/bin"
     displayName: Install Rust
-  - bash: cargo build
+  - bash: RUSTFLAGS="-D warnings" cargo build
     displayName: Build source
   - bash: cargo test
     displayName: Run tests