diff --git a/docs/protocol.md b/docs/protocol.md
index 95e0ac4f..9a7bf889 100644
--- a/docs/protocol.md
+++ b/docs/protocol.md
@@ -86,7 +86,7 @@ This sub-format is to be used when signing segwit Bitcoin transaction inputs.
             "hhhh", "hhhh", ..., "hhhh"
         ]
     },
-    "version": 4
+    "version": 5
 }
 ```