diff --git a/src/CNLoginServer.cpp b/src/CNLoginServer.cpp
index 6706006..1b3b255 100644
--- a/src/CNLoginServer.cpp
+++ b/src/CNLoginServer.cpp
@@ -135,7 +135,7 @@ void CNLoginServer::handlePacket(CNSocket* sock, CNPacketData* data) {
                 }
             } else {
                 INITSTRUCT(sP_LS2CL_REP_LOGIN_FAIL, resp);
-                U8toU16(userLogin, resp.szID);
+                U8toU16(userLogin, resp.szID, sizeof(resp.szID));
                 resp.iErrorCode = errorCode;
                 sock->sendPacket((void*)&resp, P_LS2CL_REP_LOGIN_FAIL, sizeof(sP_LS2CL_REP_LOGIN_FAIL));
             }
diff --git a/src/CNStructs.hpp b/src/CNStructs.hpp
index 9f87bb6..84e1d89 100644
--- a/src/CNStructs.hpp
+++ b/src/CNStructs.hpp
@@ -31,7 +31,7 @@
 // TODO: rewrite U16toU8 & U8toU16 to not use codecvt
 
 std::string U16toU8(char16_t* src);
-size_t U8toU16(std::string src, char16_t* des); // returns number of char16_t that was written at des
+size_t U8toU16(std::string src, char16_t* des, size_t max); // returns number of char16_t that was written at des
 time_t getTime();
 time_t getTimestamp();
 
diff --git a/src/ChatManager.cpp b/src/ChatManager.cpp
index 8b6686b..57e3a1b 100644
--- a/src/ChatManager.cpp
+++ b/src/ChatManager.cpp
@@ -246,7 +246,7 @@ void ChatManager::sendServerMessage(CNSocket* sock, std::string msg) {
 
     motd.iType = 1;
     // convert string to u16 and write it to the buffer (TODO: add sanity check to prevent buffer overflow)
-    U8toU16(msg, (char16_t*)motd.szSystemMsg);
+    U8toU16(msg, (char16_t*)motd.szSystemMsg, sizeof(motd.szSystemMsg));
 
     // send the packet :)
     sock->sendPacket((void*)&motd, P_FE2CL_PC_MOTD_LOGIN, sizeof(sP_FE2CL_PC_MOTD_LOGIN));
diff --git a/src/Database.cpp b/src/Database.cpp
index 8480f66..7e3b699 100644
--- a/src/Database.cpp
+++ b/src/Database.cpp
@@ -425,14 +425,14 @@ Player Database::DbToPlayer(DbPlayer player) {
     result.PCStyle.iClass = player.Class;
     result.PCStyle.iEyeColor = player.EyeColor;
     result.PCStyle.iFaceStyle = player.FaceStyle;
-    U8toU16(player.FirstName, result.PCStyle.szFirstName);
+    U8toU16(player.FirstName, result.PCStyle.szFirstName, sizeof(result.PCStyle.szFirstName));
     result.PCStyle.iGender = player.Gender;
     result.PCStyle.iHairColor = player.HairColor;
     result.PCStyle.iHairStyle = player.HairStyle;
     result.PCStyle.iHeight = player.Height;
     result.HP = player.HP;
     result.accountLevel = player.AccountLevel;
-    U8toU16(player.LastName, result.PCStyle.szLastName);
+    U8toU16(player.LastName, result.PCStyle.szLastName, sizeof(result.PCStyle.szLastName));
     result.level = player.Level;
     result.PCStyle.iNameCheck = player.NameCheck;
     result.PCStyle2.iPayzoneFlag = player.PayZoneFlag;
diff --git a/src/TransportManager.cpp b/src/TransportManager.cpp
index ab3fc9e..1ffaf92 100644
--- a/src/TransportManager.cpp
+++ b/src/TransportManager.cpp
@@ -162,7 +162,7 @@ void TransportManager::transportWarpHandler(CNSocket* sock, CNPacketData* data)
         INITSTRUCT(sP_FE2CL_ANNOUNCE_MSG, alert);
         alert.iAnnounceType = 0; // don't think this lets us make a confirm dialog
         alert.iDuringTime = 3;
-        U8toU16("Skyway route " + std::to_string(route.mssRouteNum) + " isn't pathed yet. You will not be charged any taros.", (char16_t*)alert.szAnnounceMsg);
+        U8toU16("Skyway route " + std::to_string(route.mssRouteNum) + " isn't pathed yet. You will not be charged any taros.", (char16_t*)alert.szAnnounceMsg, sizeof(alert.szAnnounceMsg));
         sock->sendPacket((void*)&alert, P_FE2CL_ANNOUNCE_MSG, sizeof(sP_FE2CL_ANNOUNCE_MSG));
 
         std::cout << "[WARN] MSS route " << route.mssRouteNum << " not pathed" << std::endl;
diff --git a/src/main.cpp b/src/main.cpp
index 02dcccc..3ad96e4 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -131,12 +131,15 @@ std::string U16toU8(char16_t* src) {
 }
 
 // returns number of char16_t that was written at des
-size_t U8toU16(std::string src, char16_t* des) {
+size_t U8toU16(std::string src, char16_t* des, size_t max) {
     std::wstring_convert<std::codecvt_utf8_utf16<char16_t>,char16_t> convert;
     std::u16string tmp = convert.from_bytes(src);
 
     // copy utf16 string to buffer
-    memcpy(des, tmp.c_str(), sizeof(char16_t) * tmp.length());
+    if (sizeof(char16_t) * tmp.length() > max) // make sure we don't write outside the buffer
+        memcpy(des, tmp.c_str(), sizeof(char16_t) * max);
+    else
+        memcpy(des, tmp.c_str(), sizeof(char16_t) * tmp.length());
     des[tmp.length()] = '\0';
 
     return tmp.length();