diff --git a/rehlds/engine/sv_main.cpp b/rehlds/engine/sv_main.cpp
index 1cdc033..9e95bec 100644
--- a/rehlds/engine/sv_main.cpp
+++ b/rehlds/engine/sv_main.cpp
@@ -3713,30 +3713,35 @@ int SV_CalcPing(client_t *cl)
 	return 0;
 }
 
-/* <a874a> ../engine/sv_main.c:4991 */
-void SV_FullClientUpdate(client_t *cl, sizebuf_t *sb)
+void EXT_FUNC SV_WriteFullClientUpdate_internal(IGameClient *client, char *info, size_t maxlen, sizebuf_t *sb, IGameClient *receiver)
 {
-	unsigned int i;
-	char info[MAX_INFO_STRING];
+	client_t* cl = client->GetClient();
 	MD5Context_t ctx;
 	unsigned char digest[16];
 
-	i = cl - g_psvs.clients;
-	Q_strncpy(info, cl->userinfo, sizeof(info) - 1);
-	info[sizeof(info) - 1] = 0;
-	Info_RemovePrefixedKeys(info, '_');
-
 	MD5Init(&ctx);
 	MD5Update(&ctx, (unsigned char*)cl->hashedcdkey, sizeof(cl->hashedcdkey));
 	MD5Final(digest, &ctx);
 
 	MSG_WriteByte(sb, svc_updateuserinfo);
-	MSG_WriteByte(sb, i);
+	MSG_WriteByte(sb, cl - g_psvs.clients);
 	MSG_WriteLong(sb, cl->userid);
 	MSG_WriteString(sb, info);
 	MSG_WriteBuf(sb, sizeof(digest), digest);
 }
 
+/* <a874a> ../engine/sv_main.c:4991 */
+void SV_FullClientUpdate(client_t *cl, sizebuf_t *sb)
+{
+	char info[MAX_INFO_STRING];
+
+	Q_strncpy(info, cl->userinfo, sizeof(info) - 1);
+	info[sizeof(info) - 1] = 0;
+	Info_RemovePrefixedKeys(info, '_');
+
+	g_RehldsHookchains.m_SV_WriteFullClientUpdate.callChain(SV_WriteFullClientUpdate_internal, GetRehldsApiClient(cl), info, MAX_INFO_STRING, sb, GetRehldsApiClient((sb == &g_psv.reliable_datagram) ? NULL : host_client));
+}
+
 void EXT_FUNC SV_EmitEvents_api(IGameClient *cl, packet_entities_t *pack, sizebuf_t *ms)
 {
 	SV_EmitEvents_internal(cl->GetClient(), pack, ms);
diff --git a/rehlds/public/rehlds/rehlds_api.h b/rehlds/public/rehlds/rehlds_api.h
index 57e5c43..5f93e1c 100644
--- a/rehlds/public/rehlds/rehlds_api.h
+++ b/rehlds/public/rehlds/rehlds_api.h
@@ -137,6 +137,10 @@ typedef IVoidHookChainRegistry<edict_t *> IRehldsHookRegistry_PF_Remove_I;
 typedef IVoidHookChain<edict_t *, int, const char *, float, float, int, int, int, int, const float *, edict_t *> IRehldsHook_PF_BuildSoundMsg_I;
 typedef IVoidHookChainRegistry<edict_t *, int, const char *, float, float, int, int, int, int, const float *, edict_t *> IRehldsHookRegistry_PF_BuildSoundMsg_I;
 
+//SV_WriteFullClientUpdate hook
+typedef IVoidHookChain<IGameClient *, char *, size_t, sizebuf_t *, IGameClient *> IRehldsHook_SV_WriteFullClientUpdate;
+typedef IVoidHookChainRegistry<IGameClient *, char *, size_t, sizebuf_t *, IGameClient *> IRehldsHookRegistry_SV_WriteFullClientUpdate;
+
 class IRehldsHookchains {
 public:
 	virtual ~IRehldsHookchains() { }
@@ -166,6 +170,7 @@ public:
 	virtual IRehldsHookRegistry_SV_StartSound* SV_StartSound() = 0;
 	virtual IRehldsHookRegistry_PF_Remove_I* PF_Remove_I() = 0;
 	virtual IRehldsHookRegistry_PF_BuildSoundMsg_I* PF_BuildSoundMsg_I() = 0;
+	virtual IRehldsHookRegistry_SV_WriteFullClientUpdate* SV_WriteFullClientUpdate() = 0;
 };
 
 struct RehldsFuncs_t {
diff --git a/rehlds/rehlds/rehlds_api_impl.cpp b/rehlds/rehlds/rehlds_api_impl.cpp
index 7b56673..1d051a0 100644
--- a/rehlds/rehlds/rehlds_api_impl.cpp
+++ b/rehlds/rehlds/rehlds_api_impl.cpp
@@ -249,6 +249,10 @@ IRehldsHookRegistry_PF_BuildSoundMsg_I* CRehldsHookchains::PF_BuildSoundMsg_I()
 	return &m_PF_BuildSoundMsg_I;
 }
 
+IRehldsHookRegistry_SV_WriteFullClientUpdate* CRehldsHookchains::SV_WriteFullClientUpdate() {
+	return &m_SV_WriteFullClientUpdate;
+}
+
 int EXT_FUNC CRehldsApi::GetMajorVersion()
 {
 	return REHLDS_API_VERSION_MAJOR;
diff --git a/rehlds/rehlds/rehlds_api_impl.h b/rehlds/rehlds/rehlds_api_impl.h
index fdfdc9b..a3b0cac 100644
--- a/rehlds/rehlds/rehlds_api_impl.h
+++ b/rehlds/rehlds/rehlds_api_impl.h
@@ -131,6 +131,10 @@ typedef IVoidHookChainRegistryImpl<edict_t *> CRehldsHookRegistry_PF_Remove_I;
 typedef IVoidHookChainImpl<edict_t *, int, const char *, float, float, int, int, int, int, const float *, edict_t *> CRehldsHook_PF_BuildSoundMsg_I;
 typedef IVoidHookChainRegistryImpl<edict_t *, int, const char *, float, float, int, int, int, int, const float *, edict_t *> CRehldsHookRegistry_PF_BuildSoundMsg_I;
 
+//SV_WriteFullClientUpdate hook
+typedef IVoidHookChainImpl<IGameClient *, char *, size_t, sizebuf_t *, IGameClient *> CRehldsHook_SV_WriteFullClientUpdate;
+typedef IVoidHookChainRegistryImpl<IGameClient *, char *, size_t, sizebuf_t *, IGameClient *> CRehldsHookRegistry_SV_WriteFullClientUpdate;
+
 class CRehldsHookchains : public IRehldsHookchains {
 public:
 	CRehldsHookRegistry_Steam_NotifyClientConnect m_Steam_NotifyClientConnect;
@@ -158,6 +162,7 @@ public:
 	CRehldsHookRegistry_SV_StartSound m_SV_StartSound;
 	CRehldsHookRegistry_PF_Remove_I m_PF_Remove_I;
 	CRehldsHookRegistry_PF_BuildSoundMsg_I m_PF_BuildSoundMsg_I;
+	CRehldsHookRegistry_SV_WriteFullClientUpdate m_SV_WriteFullClientUpdate;
 
 public:
 	virtual IRehldsHookRegistry_Steam_NotifyClientConnect* Steam_NotifyClientConnect();
@@ -185,6 +190,7 @@ public:
 	virtual IRehldsHookRegistry_SV_StartSound* SV_StartSound();
 	virtual IRehldsHookRegistry_PF_Remove_I* PF_Remove_I();
 	virtual IRehldsHookRegistry_PF_BuildSoundMsg_I* PF_BuildSoundMsg_I();
+	virtual IRehldsHookRegistry_SV_WriteFullClientUpdate* SV_WriteFullClientUpdate();
 };
 
 extern CRehldsHookchains g_RehldsHookchains;
diff --git a/rehlds/rehlds/rehlds_interfaces_impl.cpp b/rehlds/rehlds/rehlds_interfaces_impl.cpp
index 8eea115..768091f 100644
--- a/rehlds/rehlds/rehlds_interfaces_impl.cpp
+++ b/rehlds/rehlds/rehlds_interfaces_impl.cpp
@@ -205,6 +205,9 @@ void Rehlds_Interfaces_InitClients()
 
 IGameClient* GetRehldsApiClient(client_t* cl)
 {
+	if (cl == NULL)
+		return NULL; //I think it's logical.
+
 	int idx = cl - g_psvs.clients;
 	if (idx < 0 || idx >= g_psvs.maxclients)
 	{