diff --git a/README.txt b/README.txt
--- a/README.txt
+++ b/README.txt
@@ -1,5 +1,9 @@
+**This is not the official Firefox source code**
+
+This is just a tribute.
+
 An explanation of the Firefox Source Code Directory Structure and links to
 project pages with documentation can be found at:
 
     https://firefox-source-docs.mozilla.org/contributing/directory_structure.html