diff --git a/patches/server/Fix-CME-in-CraftPersistentDataTypeRegistry.patch b/patches/server/Fix-CME-in-CraftPersistentDataTypeRegistry.patch
new file mode 100644
index 0000000000..3418a7258f
--- /dev/null
+++ b/patches/server/Fix-CME-in-CraftPersistentDataTypeRegistry.patch
@@ -0,0 +1,19 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Gero <gecam59@gmail.com>
+Date: Sat, 2 Oct 2021 20:08:30 +0200
+Subject: [PATCH] Fix CME in CraftPersistentDataTypeRegistry
+
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataTypeRegistry.java b/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataTypeRegistry.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataTypeRegistry.java
++++ b/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataTypeRegistry.java
+@@ -0,0 +0,0 @@ public final class CraftPersistentDataTypeRegistry {
+         }
+     }
+ 
+-    private final Map<Class, TagAdapter> adapters = new HashMap<>();
++    private final Map<Class, TagAdapter> adapters = new java.util.concurrent.ConcurrentHashMap<>(); // Paper - Replace HashMap with ConcurrentHashMap to avoid CME
+ 
+     /**
+      * Creates a suitable adapter instance for the primitive class type