diff --git a/solanaceae/toxcore/tox_event_interface.hpp b/solanaceae/toxcore/tox_event_interface.hpp
index 88b345b..4777bae 100644
--- a/solanaceae/toxcore/tox_event_interface.hpp
+++ b/solanaceae/toxcore/tox_event_interface.hpp
@@ -62,6 +62,8 @@ struct ToxEventI {
 
 // defines the interface where to subscribe
 struct ToxEventProviderI {
+	static constexpr const char* version {"1"};
+
 	virtual ~ToxEventProviderI(void) {}
 	// TODO: unsub
 	virtual void subscribe(ToxEventI* object, const Tox_Event_Type event_type) = 0;
diff --git a/solanaceae/toxcore/tox_interface.hpp b/solanaceae/toxcore/tox_interface.hpp
index f8e3553..3a13eec 100644
--- a/solanaceae/toxcore/tox_interface.hpp
+++ b/solanaceae/toxcore/tox_interface.hpp
@@ -14,6 +14,8 @@
 // defines the full interface for tox
 // HACK: raw
 struct ToxI_raw {
+	static constexpr const char* version {"6"};
+
 	virtual ~ToxI_raw(void) {}
 
 	// TODO: tox version
@@ -177,6 +179,8 @@ struct ToxI_raw {
 
 // HACK: work around zppbits inability to pass string_view as parameter ( https://github.com/eyalz800/zpp_bits/issues/107 )
 struct ToxI : public ToxI_raw {
+	static constexpr const char* version {ToxI_raw::version};
+
 	Tox_Err_Set_Info toxSelfSetName_str(const std::string& name) {
 		return toxSelfSetName(name);
 	}
diff --git a/solanaceae/toxcore/tox_private_interface.hpp b/solanaceae/toxcore/tox_private_interface.hpp
index 29add51..7af91a3 100644
--- a/solanaceae/toxcore/tox_private_interface.hpp
+++ b/solanaceae/toxcore/tox_private_interface.hpp
@@ -4,6 +4,8 @@
 
 // defines the private interface for tox
 struct ToxPrivateI {
+	static constexpr const char* version {"1"};
+
 	virtual ~ToxPrivateI(void) {}
 
 	virtual uint16_t toxDHTGetNumCloselist(void) = 0;