diff --git a/common/src/main/java/com/dfsek/terra/config/builder/GeneratorBuilder.java b/common/src/main/java/com/dfsek/terra/config/builder/GeneratorBuilder.java
index c3244bf4d..4b56dd61c 100644
--- a/common/src/main/java/com/dfsek/terra/config/builder/GeneratorBuilder.java
+++ b/common/src/main/java/com/dfsek/terra/config/builder/GeneratorBuilder.java
@@ -5,11 +5,12 @@ import com.dfsek.terra.generation.config.NoiseBuilder;
 import com.dfsek.terra.generation.config.WorldGenerator;
 import parsii.eval.Scope;
 
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
 public class GeneratorBuilder {
-    private final Map<Long, WorldGenerator> gens = new HashMap<>();
+    private final Map<Long, WorldGenerator> gens = Collections.synchronizedMap(new HashMap<>());
 
     private String noiseEquation;
 
@@ -35,7 +36,9 @@ public class GeneratorBuilder {
 
 
     public WorldGenerator build(long seed) {
-        return gens.computeIfAbsent(seed, k -> new WorldGenerator(seed, noiseEquation, elevationEquation, varScope, noiseBuilderMap, palettes, slantPalettes, interpolateElevation, noise2d, base, biomeNoise.build((int) seed)));
+        synchronized(gens) {
+            return gens.computeIfAbsent(seed, k -> new WorldGenerator(seed, noiseEquation, elevationEquation, varScope, noiseBuilderMap, palettes, slantPalettes, interpolateElevation, noise2d, base, biomeNoise.build((int) seed)));
+        }
     }
 
     public void setBiomeNoise(NoiseBuilder biomeNoise) {
diff --git a/common/src/main/java/com/dfsek/terra/generation/math/SamplerCache.java b/common/src/main/java/com/dfsek/terra/generation/math/SamplerCache.java
index 10d72e027..06964ca04 100644
--- a/common/src/main/java/com/dfsek/terra/generation/math/SamplerCache.java
+++ b/common/src/main/java/com/dfsek/terra/generation/math/SamplerCache.java
@@ -10,6 +10,7 @@ import com.google.common.cache.LoadingCache;
 import net.jafama.FastMath;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -18,16 +19,20 @@ public class SamplerCache {
     private final TerraPlugin main;
 
     public SamplerCache(TerraPlugin main) {
-        containerMap = new HashMap<>();
+        containerMap = Collections.synchronizedMap(new HashMap<>());
         this.main = main;
     }
 
     public Sampler get(World world, int x, int z) {
-        return containerMap.computeIfAbsent(world.getSeed(), seed -> new Container(world)).get(x, z);
+        synchronized(containerMap) {
+            return containerMap.computeIfAbsent(world.getSeed(), seed -> new Container(world)).get(x, z);
+        }
     }
 
     public Sampler getChunk(World world, int chunkX, int chunkZ) {
-        return containerMap.computeIfAbsent(world.getSeed(), seed -> new Container(world)).getChunk(chunkX, chunkZ);
+        synchronized(containerMap) {
+            return containerMap.computeIfAbsent(world.getSeed(), seed -> new Container(world)).getChunk(chunkX, chunkZ);
+        }
     }
 
     public void clear() {