diff --git a/src/ChunkSender.cpp b/src/ChunkSender.cpp
index 43b65014a..5790accdb 100644
--- a/src/ChunkSender.cpp
+++ b/src/ChunkSender.cpp
@@ -31,7 +31,7 @@ class cNotifyChunkSender :
 	{
 		cChunkSender & ChunkSender = m_ChunkSender;
 		m_World.DoWithChunk(
-			a_ChunkX, a_ChunkZ, 
+			a_ChunkX, a_ChunkZ,
 			[&ChunkSender] (cChunk & a_Chunk) -> bool
 			{
 				ChunkSender.QueueSendChunkTo(a_Chunk.GetPosX(), a_Chunk.GetPosZ(), cChunkSender::PRIORITY_BROADCAST, a_Chunk.GetAllClients());
@@ -161,7 +161,7 @@ void cChunkSender::RemoveClient(cClientHandle * a_Client)
 		for (auto && pair : m_ChunkInfo)
 		{
 			auto && clients = pair.second.m_Clients;
-			clients.erase(a_Client); // nop for sets that do not contain a_Client
+			clients.erase(a_Client);  // nop for sets that do not contain a_Client
 		}
 
 		m_RemoveCount++;
@@ -222,9 +222,9 @@ void cChunkSender::SendChunk(int a_ChunkX, int a_ChunkZ, std::unordered_set<cCli
 {
 	
 	// Ask the client if it still wants the chunk:
-	for(auto itr = a_Clients.begin(); itr != a_Clients.end();)
+	for (auto itr = a_Clients.begin(); itr != a_Clients.end();)
 	{
-		if(!(*itr)->WantsSendChunk(a_ChunkX, a_ChunkZ))
+		if (!(*itr)->WantsSendChunk(a_ChunkX, a_ChunkZ))
 		{
 			auto toremove = itr;
 			itr++;
diff --git a/src/ClientHandle.cpp b/src/ClientHandle.cpp
index d89f7ab77..9ed89e0a3 100644
--- a/src/ClientHandle.cpp
+++ b/src/ClientHandle.cpp
@@ -456,7 +456,7 @@ bool cClientHandle::StreamNextChunk(void)
 
 				// If the chunk already loading / loaded -> skip
 				if (
-					(std::find(m_ChunksToSend.begin(), m_ChunksToSend.end(), Coords) != m_ChunksToSend.end()) ||
+					(m_ChunksToSend.find(Coords) != m_ChunksToSend.end()) ||
 					(std::find(m_LoadedChunks.begin(), m_LoadedChunks.end(), Coords) != m_LoadedChunks.end())
 				)
 				{
@@ -494,7 +494,7 @@ bool cClientHandle::StreamNextChunk(void)
 
 			// If the chunk already loading / loaded -> skip
 			if (
-				(std::find(m_ChunksToSend.begin(), m_ChunksToSend.end(), Coords) != m_ChunksToSend.end()) ||
+				(m_ChunksToSend.find(Coords) != m_ChunksToSend.end()) ||
 				(std::find(m_LoadedChunks.begin(), m_LoadedChunks.end(), Coords) != m_LoadedChunks.end())
 			)
 			{
@@ -541,7 +541,7 @@ void cClientHandle::UnloadOutOfRangeChunks(void)
 			}
 		}
 
-		for (cChunkCoordsList::iterator itr = m_ChunksToSend.begin(); itr != m_ChunksToSend.end();)
+		for (auto itr = m_ChunksToSend.begin(); itr != m_ChunksToSend.end();)
 		{
 			int DiffX = Diff((*itr).m_ChunkX, ChunkPosX);
 			int DiffZ = Diff((*itr).m_ChunkZ, ChunkPosZ);
@@ -583,7 +583,7 @@ void cClientHandle::StreamChunk(int a_ChunkX, int a_ChunkZ, cChunkSender::eChunk
 		{
 			cCSLock Lock(m_CSChunkLists);
 			m_LoadedChunks.push_back(cChunkCoords(a_ChunkX, a_ChunkZ));
-			m_ChunksToSend.push_back(cChunkCoords(a_ChunkX, a_ChunkZ));
+			m_ChunksToSend.emplace(a_ChunkX, a_ChunkZ);
 		}
 		World->SendChunkTo(a_ChunkX, a_ChunkZ, a_Priority, this);
 	}
@@ -2179,15 +2179,12 @@ void cClientHandle::SendChunkData(int a_ChunkX, int a_ChunkZ, cChunkDataSerializ
 	bool Found = false;
 	{
 		cCSLock Lock(m_CSChunkLists);
-		for (cChunkCoordsList::iterator itr = m_ChunksToSend.begin(); itr != m_ChunksToSend.end(); ++itr)
+		auto itr = m_ChunksToSend.find(cChunkCoords{a_ChunkX, a_ChunkZ});
+		if (itr != m_ChunksToSend.end())
 		{
-			if ((itr->m_ChunkX == a_ChunkX) && (itr->m_ChunkZ == a_ChunkZ))
-			{
-				m_ChunksToSend.erase(itr);
-				Found = true;
-				break;
-			}
-		}  // for itr - m_ChunksToSend[]
+			m_ChunksToSend.erase(itr);
+			Found = true;
+		}
 	}
 	if (!Found)
 	{
@@ -2950,7 +2947,7 @@ bool cClientHandle::WantsSendChunk(int a_ChunkX, int a_ChunkZ)
 	}
 	
 	cCSLock Lock(m_CSChunkLists);
-	return (std::find(m_ChunksToSend.begin(), m_ChunksToSend.end(), cChunkCoords(a_ChunkX, a_ChunkZ)) != m_ChunksToSend.end());
+	return m_ChunksToSend.find(cChunkCoords(a_ChunkX, a_ChunkZ)) != m_ChunksToSend.end();
 }
 
 
@@ -2966,9 +2963,9 @@ void cClientHandle::AddWantedChunk(int a_ChunkX, int a_ChunkZ)
 	
 	LOGD("Adding chunk [%d, %d] to wanted chunks for client %p", a_ChunkX, a_ChunkZ, this);
 	cCSLock Lock(m_CSChunkLists);
-	if (std::find(m_ChunksToSend.begin(), m_ChunksToSend.end(), cChunkCoords(a_ChunkX, a_ChunkZ)) == m_ChunksToSend.end())
+	if (m_ChunksToSend.find(cChunkCoords(a_ChunkX, a_ChunkZ)) == m_ChunksToSend.end())
 	{
-		m_ChunksToSend.push_back(cChunkCoords(a_ChunkX, a_ChunkZ));
+		m_ChunksToSend.emplace(a_ChunkX, a_ChunkZ);
 	}
 }
 
diff --git a/src/ClientHandle.h b/src/ClientHandle.h
index 13b5f87e4..27acc4d37 100644
--- a/src/ClientHandle.h
+++ b/src/ClientHandle.h
@@ -377,10 +377,10 @@ private:
 	AString m_Password;
 	Json::Value m_Properties;
 
-	cCriticalSection m_CSChunkLists;
-	cChunkCoordsList m_LoadedChunks;  // Chunks that the player belongs to
-	cChunkCoordsList m_ChunksToSend;  // Chunks that need to be sent to the player (queued because they weren't generated yet or there's not enough time to send them)
-	cChunkCoordsList m_SentChunks;    // Chunks that are currently sent to the client
+	cCriticalSection                                   m_CSChunkLists;
+	cChunkCoordsList                                   m_LoadedChunks;  // Chunks that the player belongs to
+	std::unordered_set<cChunkCoords, cChunkCoordsHash> m_ChunksToSend;  // Chunks that need to be sent to the player (queued because they weren't generated yet or there's not enough time to send them)
+	cChunkCoordsList                                   m_SentChunks;    // Chunks that are currently sent to the client
 
 	cProtocol * m_Protocol;
 
diff --git a/src/World.cpp b/src/World.cpp
index ccb6abd0b..3ff8e0723 100644
--- a/src/World.cpp
+++ b/src/World.cpp
@@ -2479,13 +2479,13 @@ void cWorld::SetChunkData(cSetChunkData & a_SetChunkData)
 	int ChunkZ = a_SetChunkData.GetChunkZ();
 	cChunkSender & ChunkSender = m_ChunkSender;
 	DoWithChunk(
-		ChunkX, ChunkZ, 
+		ChunkX, ChunkZ,
 		[&ChunkSender] (cChunk & a_Chunk) -> bool
 		{
 			if (a_Chunk.HasAnyClients())
 			{
 				ChunkSender.QueueSendChunkTo(
-					a_Chunk.GetPosX(), 
+					a_Chunk.GetPosX(),
 					a_Chunk.GetPosZ(),
 					cChunkSender::PRIORITY_BROADCAST,
 					a_Chunk.GetAllClients()