diff --git a/src/main/java/org/embeddedt/modernfix/mixin/perf/parallel_potentially_unsafe/parallel_deferred_suppliers/DispenserBlockMixin.java b/src/main/java/org/embeddedt/modernfix/mixin/perf/parallel_potentially_unsafe/parallel_deferred_suppliers/DispenserBlockMixin.java
new file mode 100644
index 00000000..459ad539
--- /dev/null
+++ b/src/main/java/org/embeddedt/modernfix/mixin/perf/parallel_potentially_unsafe/parallel_deferred_suppliers/DispenserBlockMixin.java
@@ -0,0 +1,24 @@
+package org.embeddedt.modernfix.mixin.perf.parallel_potentially_unsafe.parallel_deferred_suppliers;
+
+import net.minecraft.block.DispenserBlock;
+import net.minecraft.dispenser.IDispenseItemBehavior;
+import net.minecraft.item.Item;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+@Mixin(DispenserBlock.class)
+public class DispenserBlockMixin {
+    @Shadow private static Map<Item, IDispenseItemBehavior> DISPENSER_REGISTRY;
+
+    @Inject(method = "<clinit>", at = @At("TAIL"))
+    private static void makeMapConcurrent(CallbackInfo ci) {
+        DISPENSER_REGISTRY = new ConcurrentHashMap<>();
+    }
+}
diff --git a/src/main/resources/modernfix.mixins.json b/src/main/resources/modernfix.mixins.json
index 6a882462..d63cdc06 100644
--- a/src/main/resources/modernfix.mixins.json
+++ b/src/main/resources/modernfix.mixins.json
@@ -23,7 +23,8 @@
     "perf.parallel_potentially_unsafe.parallel_deferred_suppliers.EventDispatcherMixin",
     "perf.parallel_potentially_unsafe.parallel_blockstate_cache_rebuild.BlocksMixin",
     "perf.parallel_potentially_unsafe.parallel_blockstate_cache_rebuild.BlockCallbacksMixin",
-    "perf.parallel_potentially_unsafe.parallel_blockstate_cache_rebuild.ShapeCacheMixin"
+    "perf.parallel_potentially_unsafe.parallel_blockstate_cache_rebuild.ShapeCacheMixin",
+    "perf.parallel_potentially_unsafe.parallel_deferred_suppliers.DispenserBlockMixin"
   ],
   "client": [
     "perf.skip_first_datapack_reload.MinecraftMixin",