diff --git a/src/main/java/net/minecraft/world/chunk/storage/RegionFile.java b/src/main/java/net/minecraft/world/chunk/storage/RegionFile.java
index 7fe64c5..69c7db5 100644
--- a/src/main/java/net/minecraft/world/chunk/storage/RegionFile.java
+++ b/src/main/java/net/minecraft/world/chunk/storage/RegionFile.java
@@ -348,11 +348,12 @@
 		this.dataFile.writeInt(p_76713_3_);
 	}
 
-	public void close() throws IOException
+	public synchronized void close() throws IOException
 	{
 		if (this.dataFile != null)
 		{
 			this.dataFile.close();
+			dataFile = null;
 		}
 	}
 
diff --git a/src/main/java/net/minecraft/world/chunk/storage/RegionFileCache.java b/src/main/java/net/minecraft/world/chunk/storage/RegionFileCache.java
index 0073c45..c0f310d 100644
--- a/src/main/java/net/minecraft/world/chunk/storage/RegionFileCache.java
+++ b/src/main/java/net/minecraft/world/chunk/storage/RegionFileCache.java
@@ -8,6 +8,8 @@
 import java.util.Iterator;
 import java.util.Map;
 
+import net.minecraft.world.storage.ThreadedFileIOBase;
+
 public class RegionFileCache
 {
 	private static final Map regionsByFilename = new HashMap();
@@ -43,6 +45,14 @@
 
 	public static synchronized void clearRegionFileReferences()
 	{
+		if(!Thread.currentThread().getName().equals("File IO Thread"))
+		{
+			try
+			{
+				ThreadedFileIOBase.threadedIOInstance.waitForFinish();
+			} catch (InterruptedException ignored){}
+		}
+
 		Iterator iterator = regionsByFilename.values().iterator();
 
 		while (iterator.hasNext())