diff --git a/.travis.yml b/.travis.yml
index b9062027..6d48d543 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,7 +9,7 @@ matrix:
     script:
     - cargo test --locked
     - rustup component add rustfmt-preview
-    - cargo fmt -- --write-mode diff
+    - cargo fmt -- --check
     env: RUST_BACKTRACE=1
 
   # dist linux binary