diff --git a/bip-0138.md b/bip-0138.md
index 1cd0e1da..81740452 100644
--- a/bip-0138.md
+++ b/bip-0138.md
@@ -202,7 +202,6 @@ specification defines version `0x01`.
 
 #### Derivation Paths
 
-Note: the derivation-path vector should not contain duplicates.
 Derivation paths are optional; they can be useful to simplify the recovery process
 if one has used a non-common derivation path to derive his key.[^derivation-optional]
 
@@ -256,6 +255,11 @@ included.
 the current path.  
 `CHILD`: 4-byte big-endian unsigned integer representing a child index per BIP-32.
 
+The derivation-path vector SHOULD be encoded in lexicographic order. This avoids
+leaking information through implementation-specific ordering. The vector SHOULD NOT
+contain duplicates. Implementations SHOULD deduplicate paths during encoding or
+parsing.
+
 #### Individual Secrets
 
 At least one individual secret must be supplied.[^no-fingerprints]