diff --git a/doc/VERSIONING.md b/doc/VERSIONING.md
index 8a7aa4bf..11694c3e 100644
--- a/doc/VERSIONING.md
+++ b/doc/VERSIONING.md
@@ -1,5 +1,7 @@
 # Versioning
 
+## Package versioning
+
 When we reach 1.0, we will just adhere to [semantic
 versioning](http://semver.org/) strictly, but semver says nothing about
 versions `<1.0.0`. Thus we extend semver's rules applying them to these
@@ -10,3 +12,18 @@ a feature or a bugfix.
 Accordingly, if labels named `semver-major` or `semver-minor` are added to any
 issue or pull request before we have released `v1.0.0`, they actually assume
 minor and patch subversions.
+
+## Protocol versioning
+
+Before the package reaches version 1.0.0, the protocol version is bound to the
+first of the `metarhia-jstp` package versions that implement the same
+specification of the protocol. It would be nice to have it versioned
+independently, but it's too late to do it, since we haven't been versioning it
+from the beginning and we have made changes to the specification multiple
+times.
+
+When the package reaches 1.0.0, the protocol version will be unconditionally
+bumped to 1.0.0 too, regardless of whether `metarhia-jstp@1.0.0` brings any
+changes to the protocol.  We will then take this as a starting point and the
+protocol specification will be versioned with semver independently from the
+package.