diff --git a/solanaceae/tox_contacts/tox_contact_model2.hpp b/solanaceae/tox_contacts/tox_contact_model2.hpp
index bdf4128..868c757 100644
--- a/solanaceae/tox_contacts/tox_contact_model2.hpp
+++ b/solanaceae/tox_contacts/tox_contact_model2.hpp
@@ -19,6 +19,8 @@ class ToxContactModel2 : public ContactModel3I, public ToxEventI {
 	float _group_status_timer {0.f};
 
 	public:
+		static constexpr const char* version {"1"};
+
 		ToxContactModel2(Contact3Registry& cr, ToxI& t, ToxEventProviderI& tep);
 		virtual ~ToxContactModel2(void);