diff --git a/rdf.proto b/rdf.proto
index 2b3f4a6..c938ad1 100644
--- a/rdf.proto
+++ b/rdf.proto
@@ -246,7 +246,7 @@ message RdfStreamOptions {
   LogicalStreamType logical_type = 14;
   // Protocol version (required)
   // For Jelly 1.0.x value must be 1.
-  // For custom extensions, the value must be 1000 or higher.
+  // For custom extensions, the value must be 10000 or higher.
   uint32 version = 15;
 }