diff --git a/readme.md b/readme.md
index 2a5354d7f..05c551109 100644
--- a/readme.md
+++ b/readme.md
@@ -63,6 +63,8 @@ Here are the steps
 
 **Note** From time to time, the dependencies might change, so just run `install_dependencies.sh` again if things are not working.
 
+**Warning:** If you edit Makefiles or shell scripts, make sure you are using an editor that saves the files with Unix line endings. Otherwise the compilation might not work.
+
 
 ### Windows (Vista and later)
 1. If you have ever installed WinAVR, uninstall it.