diff --git a/Spigot-Server-Patches/0386-Fix-FileIOThread-concurrency-issues.patch b/Spigot-Server-Patches/0386-Fix-FileIOThread-concurrency-issues.patch
new file mode 100644
index 0000000000..f122647c3b
--- /dev/null
+++ b/Spigot-Server-Patches/0386-Fix-FileIOThread-concurrency-issues.patch
@@ -0,0 +1,35 @@
+From c829c08588842173ed4ce8d43a61f25e2a6a848c Mon Sep 17 00:00:00 2001
+From: Shane Freeder <theboyetronic@gmail.com>
+Date: Wed, 3 Oct 2018 19:04:53 +0100
+Subject: [PATCH] Fix FileIOThread concurrency issues
+
+FileIOThread was using two volatile counters in order to track if
+any pending work was in the queue, this causes potential concurrency
+issues when this counter is updated from multiple threads, potentially
+causing these counters to desync due to the unsafe volatile update
+
+diff --git a/src/main/java/net/minecraft/server/FileIOThread.java b/src/main/java/net/minecraft/server/FileIOThread.java
+index 97917551..1959bc06 100644
+--- a/src/main/java/net/minecraft/server/FileIOThread.java
++++ b/src/main/java/net/minecraft/server/FileIOThread.java
+@@ -9,7 +9,7 @@ import org.apache.logging.log4j.Logger;
+ public class FileIOThread implements Runnable {
+     private static final Logger a = LogManager.getLogger();
+     private static final FileIOThread b = new FileIOThread();
+-    private final List<IAsyncChunkSaver> c = Collections.synchronizedList(Lists.newArrayList());
++    private final List<IAsyncChunkSaver> c = Collections.synchronizedList(Lists.newArrayList()); private List<IAsyncChunkSaver> getThreadedIOQueue() { return c; } // Paper - OBFHELPER
+     private volatile long d;
+     private volatile long e;
+     private volatile boolean f;
+@@ -72,7 +72,7 @@ public class FileIOThread implements Runnable {
+     public void b() throws InterruptedException {
+         this.f = true;
+ 
+-        while(this.d != this.e) {
++        while(!this.getThreadedIOQueue().isEmpty()) { // Paper - check actual list size
+             Thread.sleep(10L);
+         }
+ 
+-- 
+2.19.0
+