diff --git a/.build.yml b/.build.yml
index be80c59..44869c1 100644
--- a/.build.yml
+++ b/.build.yml
@@ -9,3 +9,4 @@ tasks:
       cd soju
       go test -v ./...
       scdoc <doc/soju.1.scd >/dev/null
+      test -z $(gofmt -l .)