diff --git a/solanaceae/ngc_ext/ngcext.cpp b/solanaceae/ngc_ext/ngcext.cpp
index 34e3850..55e2044 100644
--- a/solanaceae/ngc_ext/ngcext.cpp
+++ b/solanaceae/ngc_ext/ngcext.cpp
@@ -3,9 +3,11 @@
 #include <iostream>
 #include <cassert>
 
-NGCEXTEventProvider::NGCEXTEventProvider(ToxI& t, ToxEventProviderI& tep) : _t(t), _tep(tep) {
-	_tep.subscribe(this, Tox_Event_Type::TOX_EVENT_GROUP_CUSTOM_PACKET);
-	_tep.subscribe(this, Tox_Event_Type::TOX_EVENT_GROUP_CUSTOM_PRIVATE_PACKET);
+NGCEXTEventProvider::NGCEXTEventProvider(ToxI& t, ToxEventProviderI& tep) : _t(t), _tep(tep), _tep_sr(_tep.newSubRef(this)) {
+	_tep_sr
+		.subscribe(Tox_Event_Type::TOX_EVENT_GROUP_CUSTOM_PACKET)
+		.subscribe(Tox_Event_Type::TOX_EVENT_GROUP_CUSTOM_PRIVATE_PACKET)
+	;
 }
 
 #define _DATA_HAVE(x, error) if ((data_size - curser) < (x)) { error; }
diff --git a/solanaceae/ngc_ext/ngcext.hpp b/solanaceae/ngc_ext/ngcext.hpp
index 61b20b9..aafc3fb 100644
--- a/solanaceae/ngc_ext/ngcext.hpp
+++ b/solanaceae/ngc_ext/ngcext.hpp
@@ -314,6 +314,7 @@ using NGCEXTEventProviderI = EventProviderI<NGCEXTEventI>;
 class NGCEXTEventProvider : public ToxEventI, public NGCEXTEventProviderI {
 	ToxI& _t;
 	ToxEventProviderI& _tep;
+	ToxEventProviderI::SubscriptionReference _tep_sr;
 
 	public:
 		NGCEXTEventProvider(ToxI& t, ToxEventProviderI& tep);
diff --git a/solanaceae/ngc_ft1/ngcft1.cpp b/solanaceae/ngc_ft1/ngcft1.cpp
index 3683252..b5b16d3 100644
--- a/solanaceae/ngc_ft1/ngcft1.cpp
+++ b/solanaceae/ngc_ft1/ngcft1.cpp
@@ -251,16 +251,18 @@ NGCFT1::NGCFT1(
 	ToxI& t,
 	ToxEventProviderI& tep,
 	NGCEXTEventProvider& neep
-) : _t(t), _tep(tep), _neep(neep)
+) : _t(t), _tep(tep), _tep_sr(_tep.newSubRef(this)), _neep(neep), _neep_sr(_neep.newSubRef(this))
 {
-	_neep.subscribe(this, NGCEXT_Event::FT1_REQUEST);
-	_neep.subscribe(this, NGCEXT_Event::FT1_INIT);
-	_neep.subscribe(this, NGCEXT_Event::FT1_INIT_ACK);
-	_neep.subscribe(this, NGCEXT_Event::FT1_DATA);
-	_neep.subscribe(this, NGCEXT_Event::FT1_DATA_ACK);
-	_neep.subscribe(this, NGCEXT_Event::FT1_MESSAGE);
+	_neep_sr
+		.subscribe(NGCEXT_Event::FT1_REQUEST)
+		.subscribe(NGCEXT_Event::FT1_INIT)
+		.subscribe(NGCEXT_Event::FT1_INIT_ACK)
+		.subscribe(NGCEXT_Event::FT1_DATA)
+		.subscribe(NGCEXT_Event::FT1_DATA_ACK)
+		.subscribe(NGCEXT_Event::FT1_MESSAGE)
+	;
 
-	_tep.subscribe(this, Tox_Event_Type::TOX_EVENT_GROUP_PEER_EXIT);
+	_tep_sr.subscribe(Tox_Event_Type::TOX_EVENT_GROUP_PEER_EXIT);
 }
 
 float NGCFT1::iterate(float time_delta) {
diff --git a/solanaceae/ngc_ft1/ngcft1.hpp b/solanaceae/ngc_ft1/ngcft1.hpp
index 2c81a03..dd0a0d6 100644
--- a/solanaceae/ngc_ft1/ngcft1.hpp
+++ b/solanaceae/ngc_ft1/ngcft1.hpp
@@ -132,7 +132,9 @@ using NGCFT1EventProviderI = EventProviderI<NGCFT1EventI>;
 class NGCFT1 : public ToxEventI, public NGCEXTEventI, public NGCFT1EventProviderI {
 	ToxI& _t;
 	ToxEventProviderI& _tep;
+	ToxEventProviderI::SubscriptionReference _tep_sr;
 	NGCEXTEventProvider& _neep; // not the interface?
+	NGCEXTEventProvider::SubscriptionReference _neep_sr;
 
 	std::default_random_engine _rng{std::random_device{}()};
 
diff --git a/solanaceae/ngc_ft1_sha1/sha1_ngcft1.cpp b/solanaceae/ngc_ft1_sha1/sha1_ngcft1.cpp
index e04aad0..1e249bb 100644
--- a/solanaceae/ngc_ft1_sha1/sha1_ngcft1.cpp
+++ b/solanaceae/ngc_ft1_sha1/sha1_ngcft1.cpp
@@ -201,36 +201,49 @@ SHA1_NGCFT1::SHA1_NGCFT1(
 	NGCEXTEventProvider& neep
 ) :
 	_os(os),
+	_os_sr(_os.newSubRef(this)),
 	_cr(cr),
 	_rmm(rmm),
+	_rmm_sr(_rmm.newSubRef(this)),
 	_nft(nft),
+	_nft_sr(_nft.newSubRef(this)),
 	_tcm(tcm),
 	_tep(tep),
+	_tep_sr(_tep.newSubRef(this)),
 	_neep(neep),
+	_neep_sr(_neep.newSubRef(this)),
 	_mfb(os)
 {
+	_os_sr
 	// TODO: also create and destroy
-	//_os.subscribe(this, ObjectStore_Event::object_construct);
-	_os.subscribe(this, ObjectStore_Event::object_update);
-	//_os.subscribe(this, ObjectStore_Event::object_destroy);
+	//	.subscribe(ObjectStore_Event::object_construct)
+		.subscribe(ObjectStore_Event::object_update)
+	//	.subscribe(ObjectStore_Event::object_destroy)
+	;
 
-	_nft.subscribe(this, NGCFT1_Event::recv_request);
-	_nft.subscribe(this, NGCFT1_Event::recv_init);
-	_nft.subscribe(this, NGCFT1_Event::recv_data);
-	_nft.subscribe(this, NGCFT1_Event::send_data);
-	_nft.subscribe(this, NGCFT1_Event::recv_done);
-	_nft.subscribe(this, NGCFT1_Event::send_done);
-	_nft.subscribe(this, NGCFT1_Event::recv_message);
+	_nft_sr
+		.subscribe(NGCFT1_Event::recv_request)
+		.subscribe(NGCFT1_Event::recv_init)
+		.subscribe(NGCFT1_Event::recv_data)
+		.subscribe(NGCFT1_Event::send_data)
+		.subscribe(NGCFT1_Event::recv_done)
+		.subscribe(NGCFT1_Event::send_done)
+		.subscribe(NGCFT1_Event::recv_message)
+	;
 
-	_rmm.subscribe(this, RegistryMessageModel_Event::send_file_path);
+	_rmm_sr.subscribe(RegistryMessageModel_Event::send_file_path);
 
-	_tep.subscribe(this, Tox_Event_Type::TOX_EVENT_GROUP_PEER_JOIN);
-	_tep.subscribe(this, Tox_Event_Type::TOX_EVENT_GROUP_PEER_EXIT);
+	_tep_sr
+		.subscribe(Tox_Event_Type::TOX_EVENT_GROUP_PEER_JOIN)
+		.subscribe(Tox_Event_Type::TOX_EVENT_GROUP_PEER_EXIT)
+	;
 
-	_neep.subscribe(this, NGCEXT_Event::FT1_HAVE);
-	_neep.subscribe(this, NGCEXT_Event::FT1_BITSET);
-	_neep.subscribe(this, NGCEXT_Event::FT1_HAVE_ALL);
-	_neep.subscribe(this, NGCEXT_Event::PC1_ANNOUNCE);
+	_neep_sr
+		.subscribe(NGCEXT_Event::FT1_HAVE)
+		.subscribe(NGCEXT_Event::FT1_BITSET)
+		.subscribe(NGCEXT_Event::FT1_HAVE_ALL)
+		.subscribe(NGCEXT_Event::PC1_ANNOUNCE)
+	;
 }
 
 float SHA1_NGCFT1::iterate(float delta) {
diff --git a/solanaceae/ngc_ft1_sha1/sha1_ngcft1.hpp b/solanaceae/ngc_ft1_sha1/sha1_ngcft1.hpp
index 01f0a4b..5ccc28e 100644
--- a/solanaceae/ngc_ft1_sha1/sha1_ngcft1.hpp
+++ b/solanaceae/ngc_ft1_sha1/sha1_ngcft1.hpp
@@ -22,13 +22,18 @@
 
 class SHA1_NGCFT1 : public ToxEventI, public RegistryMessageModelEventI, public ObjectStoreEventI, public NGCFT1EventI, public NGCEXTEventI {
 	ObjectStore2& _os;
+	ObjectStore2::SubscriptionReference _os_sr;
 	// TODO: backend abstraction
 	Contact3Registry& _cr;
 	RegistryMessageModelI& _rmm;
+	RegistryMessageModelI::SubscriptionReference _rmm_sr;
 	NGCFT1& _nft;
+	NGCFT1::SubscriptionReference _nft_sr;
 	ToxContactModel2& _tcm;
 	ToxEventProviderI& _tep;
+	ToxEventProviderI::SubscriptionReference _tep_sr;
 	NGCEXTEventProvider& _neep;
+	NGCEXTEventProvider::SubscriptionReference _neep_sr;
 
 	Backends::SHA1MappedFilesystem _mfb;