diff --git a/CLAUDE.md b/CLAUDE.md
index f57909b..29703b6 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -105,6 +105,11 @@ po/
 
 5. **Module Installation**: Python modules are installed to `{datadir}/roster/roster/` and the launcher script is configured with the correct Python interpreter path.
 
+## Communication
+
+- Communicate with the user in **English**
+- Git commit messages: **concise, single-line, in English**
+
 ## Adding New Python Modules
 
 When adding new `.py` files to `src/`: