diff --git a/TESTING.md b/TESTING.md
index fde97a4..740e80b 100644
--- a/TESTING.md
+++ b/TESTING.md
@@ -112,6 +112,7 @@ cargo fmt --check
 cargo test --workspace
 cargo clippy --workspace --all-targets -- -D warnings
 cargo build --release -p lanparty-relay -p lanparty-gateway
+git diff --check
 ```
 
 The workspace tests include real client/relay/gateway session coverage for