diff --git a/cmd/plexum-harborforge-plugin/main.go b/cmd/plexum-harborforge-plugin/main.go
index ac27edd..282e5a2 100644
--- a/cmd/plexum-harborforge-plugin/main.go
+++ b/cmd/plexum-harborforge-plugin/main.go
@@ -230,6 +230,10 @@ func (p *harborForgePlugin) RenderDynamicSubblock(ctx context.Context, agentID,
 	p.agentSession.Store(agentID, sessionID)
 
 	if name != "kb-block" {
+		// Host shouldn't request unknown subblock names per manifest
+		// contract, but log defensively so operator notices wiring drift.
+		p.host.Log("warn", "dynamic-block render: unknown subblock name",
+			map[string]any{"agent": agentID, "session": sessionID, "name": name})
 		return "", nil
 	}
 	block, err := kbblock.Open(p.profileRoot, agentID, sessionID)