diff --git a/.gitignore b/.gitignore
index c04b756..3ca9e3b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,6 @@
 /target/
 /spike/out/
 /.state/
+
+# Local secrets and accounts (for example mattermost.env): never commit.
+*.env