diff --git a/src/client.cpp b/src/client.cpp
index 8a5a09f2fb..3958fd1b62 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -699,6 +699,7 @@ void Client::step(float dtime)
 				<<std::endl;*/
 		
 		int num_processed_meshes = 0;
+		UniqueQueue<v3s16> got_blocks;
 		while(!m_mesh_update_thread.m_queue_out.empty())
 		{
 			num_processed_meshes++;
@@ -722,6 +723,13 @@ void Client::step(float dtime)
 			}
 			if(r.ack_block_to_server)
 			{
+				got_blocks.push_back(r.p);
+				if (got_blocks.size() >= 255)
+					break;
+			}
+		}
+		u32 got_blocks_size = got_blocks.size();
+		if (got_blocks_size) {
 				/*infostream<<"Client: ACK block ("<<r.p.X<<","<<r.p.Y
 						<<","<<r.p.Z<<")"<<std::endl;*/
 				/*
@@ -735,15 +743,17 @@ void Client::step(float dtime)
 					[3+6*i] u16 vrange
 					...
 				*/
-				u32 replysize = 2+1+6+2;
+				u32 replysize = 2+1+(6*got_blocks_size)+2;
 				SharedBuffer<u8> reply(replysize);
 				writeU16(&reply[0], TOSERVER_GOTBLOCKS);
-				reply[2] = 1;
-				writeV3S16(&reply[3], r.p);
-				writeU16(&reply[2+1+(6*reply[2])], (int)m_env.getClientMap().getControl().wanted_range);
+				reply[2] = got_blocks_size;
+				u32 i=0;
+				while (got_blocks.size())
+					writeV3S16(&reply[3+(6*i++)], got_blocks.pop_front());
+				writeU16(&reply[2+1+(6*got_blocks_size)], (int)m_env.getClientMap().getControl().wanted_range);
 				// Send as reliable
 				m_con.Send(PEER_ID_SERVER, 1, reply, true);
-			}
+			
 		}
 		if(num_processed_meshes > 0)
 			g_profiler->graphAdd("num_processed_meshes", num_processed_meshes);