diff --git a/src/main/java/org/embeddedt/modernfix/common/mixin/perf/cache_strongholds/ChunkGeneratorMixin.java b/src/main/java/org/embeddedt/modernfix/common/mixin/perf/cache_strongholds/ChunkGeneratorMixin.java
index 65d5b383..0b865124 100644
--- a/src/main/java/org/embeddedt/modernfix/common/mixin/perf/cache_strongholds/ChunkGeneratorMixin.java
+++ b/src/main/java/org/embeddedt/modernfix/common/mixin/perf/cache_strongholds/ChunkGeneratorMixin.java
@@ -4,9 +4,9 @@ import com.llamalad7.mixinextras.injector.wrapmethod.WrapMethod;
 import com.llamalad7.mixinextras.injector.wrapoperation.Operation;
 import net.minecraft.Util;
 import net.minecraft.core.Holder;
-import net.minecraft.core.RegistryAccess;
 import net.minecraft.nbt.*;
 import net.minecraft.resources.RegistryOps;
+import net.minecraft.server.MinecraftServer;
 import net.minecraft.world.level.ChunkPos;
 import net.minecraft.world.level.biome.BiomeSource;
 import net.minecraft.world.level.chunk.ChunkGeneratorStructureState;
@@ -41,22 +41,23 @@ public class ChunkGeneratorMixin implements IChunkGenerator {
     private BiomeSource biomeSource;
 
     private Path mfix$dimensionPath;
-    private RegistryAccess.Frozen mfix$registryAccess;
+    private MinecraftServer mfix$server;
+
     private SoftReference<Map<String, List<ChunkPos>>> mfix$cachedPositions = new SoftReference<>(null);
 
     private static final String CACHE_FILENAME = "mfix_stronghold_cache_v2.nbt";
 
     @Override
-    public void mfix$setStrongholdCachePath(Path cachePath, RegistryAccess.Frozen registryAccess) {
+    public void mfix$setStrongholdCachePath(Path cachePath, MinecraftServer server) {
         this.mfix$dimensionPath = cachePath;
-        this.mfix$registryAccess = registryAccess;
+        this.mfix$server = server;
     }
 
     @WrapMethod(method = "generateRingPositions")
     private CompletableFuture<List<ChunkPos>> modernfix$cacheRingPositions(Holder<StructureSet> structureSet,
                                                                           ConcentricRingsStructurePlacement placement,
                                                                           Operation<CompletableFuture<List<ChunkPos>>> original) {
-        if (this.mfix$registryAccess == null || this.mfix$dimensionPath == null) {
+        if (this.mfix$server == null || this.mfix$dimensionPath == null) {
             return original.call(structureSet, placement);
         }
 
@@ -69,14 +70,18 @@ public class ChunkGeneratorMixin implements IChunkGenerator {
             return CompletableFuture.completedFuture(List.copyOf(cached));
         }
 
+        var server = this.mfix$server;
         return original.call(structureSet, placement).thenApplyAsync(positions -> {
-            mfix$writeToCache(cacheKey, positions);
+            // Skip write if server exited before we finished
+            if (server.isRunning()) {
+                mfix$writeToCache(cacheKey, positions);
+            }
             return positions;
         }, Util.ioPool());
     }
 
     private String mfix$makeCacheKey(ConcentricRingsStructurePlacement placement) {
-        RegistryOps<Tag> ops = RegistryOps.create(NbtOps.INSTANCE, this.mfix$registryAccess);
+        RegistryOps<Tag> ops = RegistryOps.create(NbtOps.INSTANCE, this.mfix$server.registryAccess());
         String placementKey = ConcentricRingsStructurePlacement.CODEC.encodeStart(ops, placement)
                 .result().map(Tag::toString).orElse(null);
         String biomeSourceKey = BiomeSource.CODEC.encodeStart(ops, this.biomeSource)
diff --git a/src/main/java/org/embeddedt/modernfix/common/mixin/perf/cache_strongholds/ServerLevelMixin.java b/src/main/java/org/embeddedt/modernfix/common/mixin/perf/cache_strongholds/ServerLevelMixin.java
index 8505303e..dcd2b2f8 100644
--- a/src/main/java/org/embeddedt/modernfix/common/mixin/perf/cache_strongholds/ServerLevelMixin.java
+++ b/src/main/java/org/embeddedt/modernfix/common/mixin/perf/cache_strongholds/ServerLevelMixin.java
@@ -24,7 +24,7 @@ public class ServerLevelMixin {
                                      @Local(ordinal = 0, argsOnly = true) LevelStorageSource.LevelStorageAccess levelStorageAccess,
                                      @Local(ordinal = 0, argsOnly = true) ResourceKey<Level> dimension,
                                      @Local(ordinal = 0, argsOnly = true) MinecraftServer server) {
-        ((IChunkGenerator)instance).mfix$setStrongholdCachePath(levelStorageAccess.getDimensionPath(dimension), server.registryAccess());
+        ((IChunkGenerator)instance).mfix$setStrongholdCachePath(levelStorageAccess.getDimensionPath(dimension), server);
         original.call(instance);
     }
 }
diff --git a/src/main/java/org/embeddedt/modernfix/duck/IChunkGenerator.java b/src/main/java/org/embeddedt/modernfix/duck/IChunkGenerator.java
index 3cf83acc..312c5b44 100644
--- a/src/main/java/org/embeddedt/modernfix/duck/IChunkGenerator.java
+++ b/src/main/java/org/embeddedt/modernfix/duck/IChunkGenerator.java
@@ -1,9 +1,9 @@
 package org.embeddedt.modernfix.duck;
 
-import net.minecraft.core.RegistryAccess;
+import net.minecraft.server.MinecraftServer;
 
 import java.nio.file.Path;
 
 public interface IChunkGenerator {
-    void mfix$setStrongholdCachePath(Path cachePath, RegistryAccess.Frozen registryAccess);
+    void mfix$setStrongholdCachePath(Path cachePath, MinecraftServer server);
 }