diff --git a/Coding-Guidelines.md b/Coding-Guidelines.md
index 0c629e2..11950eb 100644
--- a/Coding-Guidelines.md
+++ b/Coding-Guidelines.md
@@ -4,4 +4,7 @@
 
 # Indentation
 
-Convention is to use 2 spaces, however 4 spaces are also fine.
\ No newline at end of file
+Convention is to use 2 spaces, however 4 spaces are also fine.
+
+Tabs are _not_ allowed.
+