diff --git a/spec.md b/spec.md
index 49d7f0f..628f058 100644
--- a/spec.md
+++ b/spec.md
@@ -6,6 +6,7 @@ An instruction is:
 12 bits - y
 24 bits - rgb
 ```
+Integers are big endian.
 
 ## Encrypted
 The encrypted protocol works by encapsulating an unencrypted packet.