diff --git a/server/accounts/account_manager.cpp b/server/accounts/account_manager.cpp
index 22538bb..7b2a423 100644
--- a/server/accounts/account_manager.cpp
+++ b/server/accounts/account_manager.cpp
@@ -200,7 +200,7 @@ void AccountManager::UnloadAll() {
 	elementMap.clear();
 }
 
-void AccountManager::UnloadIf(std::function<bool(std::pair<const int, AccountData>)> fn) {
+void AccountManager::UnloadIf(std::function<bool(std::pair<const int, AccountData const&>)> fn) {
 	//replicate std::remove_if, using custom code
 	std::map<int, AccountData>::iterator it = elementMap.begin();
 	while (it != elementMap.end()) {
diff --git a/server/accounts/account_manager.hpp b/server/accounts/account_manager.hpp
index ad65836..629bc36 100644
--- a/server/accounts/account_manager.hpp
+++ b/server/accounts/account_manager.hpp
@@ -44,7 +44,7 @@ public:
 	void Delete(int uid);
 
 	void UnloadAll();
-	void UnloadIf(std::function<bool(std::pair<const int, AccountData>)> fn);
+	void UnloadIf(std::function<bool(std::pair<const int, AccountData const&>)> fn);
 
 	//accessors and mutators
 	AccountData* Get(int uid);
diff --git a/server/characters/character_manager.cpp b/server/characters/character_manager.cpp
index 53edc9c..df8819f 100644
--- a/server/characters/character_manager.cpp
+++ b/server/characters/character_manager.cpp
@@ -229,7 +229,7 @@ void CharacterManager::UnloadAll() {
 	elementMap.clear();
 }
 
-void CharacterManager::UnloadIf(std::function<bool(std::pair<const int, CharacterData>)> fn) {
+void CharacterManager::UnloadIf(std::function<bool(std::pair<const int, CharacterData const&>)> fn) {
 	std::map<int, CharacterData>::iterator it = elementMap.begin();
 	while (it != elementMap.end()) {
 		if (fn(*it)) {
diff --git a/server/characters/character_manager.hpp b/server/characters/character_manager.hpp
index 2263d46..959dfbc 100644
--- a/server/characters/character_manager.hpp
+++ b/server/characters/character_manager.hpp
@@ -44,7 +44,7 @@ public:
 	void Delete(int uid);
 
 	void UnloadAll();
-	void UnloadIf(std::function<bool(std::pair<const int, CharacterData>)> fn);
+	void UnloadIf(std::function<bool(std::pair<const int, CharacterData const&>)> fn);
 
 	//accessors and mutators
 	CharacterData* Get(int uid);
diff --git a/server/clients/client_manager.cpp b/server/clients/client_manager.cpp
index a1c1808..488a742 100644
--- a/server/clients/client_manager.cpp
+++ b/server/clients/client_manager.cpp
@@ -73,7 +73,7 @@ void ClientManager::UnloadAll() {
 	elementMap.clear();
 }
 
-void ClientManager::UnloadIf(std::function<bool(std::pair<const int, ClientData>)> fn) {
+void ClientManager::UnloadIf(std::function<bool(std::pair<const int, ClientData const&>)> fn) {
 	std::map<int, ClientData>::iterator it = elementMap.begin();
 	while (it != elementMap.end()) {
 		if (fn(*it)) {
diff --git a/server/clients/client_manager.hpp b/server/clients/client_manager.hpp
index 165199b..320499f 100644
--- a/server/clients/client_manager.hpp
+++ b/server/clients/client_manager.hpp
@@ -42,7 +42,7 @@ public:
 	void Unload(int uid);
 
 	void UnloadAll();
-	void UnloadIf(std::function<bool(std::pair<const int, ClientData>)> fn);
+	void UnloadIf(std::function<bool(std::pair<const int, ClientData const&>)> fn);
 
 	//accessors & mutators
 	ClientData* Get(int uid);
diff --git a/server/monsters/monster_manager.cpp b/server/monsters/monster_manager.cpp
index dd88668..0cc78ce 100644
--- a/server/monsters/monster_manager.cpp
+++ b/server/monsters/monster_manager.cpp
@@ -45,7 +45,7 @@ void MonsterManager::UnloadAll() {
 	//TODO
 }
 
-void MonsterManager::UnloadIf(std::function<bool(std::pair<const int, MonsterData>)> fn) {
+void MonsterManager::UnloadIf(std::function<bool(std::pair<const int, MonsterData const&>)> fn) {
 	//TODO
 }
 
diff --git a/server/monsters/monster_manager.hpp b/server/monsters/monster_manager.hpp
index 24f980f..d8c7849 100644
--- a/server/monsters/monster_manager.hpp
+++ b/server/monsters/monster_manager.hpp
@@ -47,7 +47,7 @@ public:
 	void Delete(int uid);
 
 	void UnloadAll();
-	void UnloadIf(std::function<bool(std::pair<const int, MonsterData>)> fn);
+	void UnloadIf(std::function<bool(std::pair<const int, MonsterData const&>)> fn);
 
 	//accessors & mutators
 	MonsterData* Get(int uid);
diff --git a/server/rooms/room_manager.cpp b/server/rooms/room_manager.cpp
index 4ce2dff..56a3f65 100644
--- a/server/rooms/room_manager.cpp
+++ b/server/rooms/room_manager.cpp
@@ -45,7 +45,7 @@ void RoomManager::UnloadAll() {
 	elementMap.clear();
 }
 
-void RoomManager::UnloadIf(std::function<bool(std::pair<const int,RoomData>)> fn) {
+void RoomManager::UnloadIf(std::function<bool(std::pair<const int, RoomData const&>)> fn) {
 	std::map<int, RoomData>::iterator it = elementMap.begin();
 	while (it != elementMap.end()) {
 		if (fn(*it)) {
diff --git a/server/rooms/room_manager.hpp b/server/rooms/room_manager.hpp
index 9f9f37c..8bf1cc6 100644
--- a/server/rooms/room_manager.hpp
+++ b/server/rooms/room_manager.hpp
@@ -40,7 +40,7 @@ public:
 	int Create(std::string name, std::string tileset);
 
 	void UnloadAll();
-	void UnloadIf(std::function<bool(std::pair<const int,RoomData>)> fn);
+	void UnloadIf(std::function<bool(std::pair<const int, RoomData const&>)> fn);
 
 	//accessors and mutators
 	RoomData* Get(int uid);
diff --git a/server/server_methods.cpp b/server/server_methods.cpp
index 1a97a68..e8f197f 100644
--- a/server/server_methods.cpp
+++ b/server/server_methods.cpp
@@ -97,7 +97,7 @@ void ServerApplication::HandleShutdownRequest(ClientPacket* const argPacket) {
 //-------------------------
 
 void ServerApplication::FullClientUnload(int index) {
-	clientMgr.UnloadIf([&](std::pair<const int, ClientData> client) -> bool {
+	clientMgr.UnloadIf([&](std::pair<const int, ClientData const&> client) -> bool {
 		//skip the wrong clients
 		if (client.first != index) {
 			return false;
@@ -120,7 +120,7 @@ void ServerApplication::FullClientUnload(int index) {
 }
 
 void ServerApplication::FullAccountUnload(int index) {
-	accountMgr.UnloadIf([&](std::pair<const int, AccountData> account) -> bool {
+	accountMgr.UnloadIf([&](std::pair<const int, AccountData const&> account) -> bool {
 		//skip the wrong accounts
 		if (account.first != index) {
 			return false;
@@ -143,7 +143,7 @@ void ServerApplication::FullAccountUnload(int index) {
 }
 
 void ServerApplication::FullCharacterUnload(int index) {
-	characterMgr.UnloadIf([&](std::pair<const int, CharacterData> character) -> bool {
+	characterMgr.UnloadIf([&](std::pair<const int, CharacterData const&> character) -> bool {
 		//skip the wrong characters
 		if (character.first != index) {
 			return false;
diff --git a/server/waypoints/waypoint_manager.cpp b/server/waypoints/waypoint_manager.cpp
index fe0889b..a89165b 100644
--- a/server/waypoints/waypoint_manager.cpp
+++ b/server/waypoints/waypoint_manager.cpp
@@ -45,7 +45,7 @@ void WaypointManager::UnloadAll() {
 	//TODO
 }
 
-void WaypointManager::UnloadIf(std::function<bool(std::pair<const int, WaypointData>)> fn) {
+void WaypointManager::UnloadIf(std::function<bool(std::pair<const int, WaypointData const&>)> fn) {
 	//TODO
 }
 
diff --git a/server/waypoints/waypoint_manager.hpp b/server/waypoints/waypoint_manager.hpp
index 0e51d3a..38aea9e 100644
--- a/server/waypoints/waypoint_manager.hpp
+++ b/server/waypoints/waypoint_manager.hpp
@@ -47,7 +47,7 @@ public:
 	void Delete(int uid);
 
 	void UnloadAll();
-	void UnloadIf(std::function<bool(std::pair<const int, WaypointData>)> fn);
+	void UnloadIf(std::function<bool(std::pair<const int, WaypointData const&>)> fn);
 
 	//accessors & mutators
 	WaypointData* Get(int uid);