diff --git a/src/api.ml b/src/api.ml
index 80aedc27..519cfb38 100644
--- a/src/api.ml
+++ b/src/api.ml
@@ -7,7 +7,7 @@
      - payto_uri
      - uri *)
 
-let protocol_version = "31"
+let protocol_version = "31:0:0"
 
 open Crypto
 open Signatures