diff --git a/source/World.cpp b/source/World.cpp
index 3f5e604bf..a573653d7 100644
--- a/source/World.cpp
+++ b/source/World.cpp
@@ -1599,13 +1599,19 @@ void cWorld::SetChunkData(
 		m_Generator.GenerateBiomes(a_ChunkX, a_ChunkZ, BiomeMap);
 	}
 	
-	m_ChunkMap->SetChunkData(
-		a_ChunkX, a_ChunkY, a_ChunkZ, 
-		a_BlockTypes, a_BlockMeta, a_BlockLight, a_BlockSkyLight,
-		a_HeightMap, *Biomes,
-		a_Entities, a_BlockEntities,
-		a_MarkDirty
-	);
+	{
+		// _X: 2013_04_01: Hotfix for FS #347 - deadlock between the anvil loader thread and the tick thread
+		// By locking the entities here, we break one of the 3 conditions needed for the deadlock
+		cCSLock Lock(m_CSEntities);
+		
+		m_ChunkMap->SetChunkData(
+			a_ChunkX, a_ChunkY, a_ChunkZ, 
+			a_BlockTypes, a_BlockMeta, a_BlockLight, a_BlockSkyLight,
+			a_HeightMap, *Biomes,
+			a_Entities, a_BlockEntities,
+			a_MarkDirty
+		);
+	}
 	
 	// If a client is requesting this chunk, send it to them:
 	if (m_ChunkMap->HasChunkAnyClients(a_ChunkX, a_ChunkY, a_ChunkZ))