diff --git a/docs/emails/cryptography/1.md b/docs/emails/cryptography/1.md
index 1ccaf72..adf622c 100644
--- a/docs/emails/cryptography/1.md
+++ b/docs/emails/cryptography/1.md
@@ -2,4 +2,5 @@
 layout: default
 title: Bitcoin P2P e-cash paper
 grand_parent: Cryptography
+nav_order: 1
 ---