diff --git a/core/src/main/java/net/momirealms/craftengine/core/world/chunk/client/ClientChunk.java b/core/src/main/java/net/momirealms/craftengine/core/world/chunk/client/ClientChunk.java
index 03e0ac6ad..b99d3a574 100644
--- a/core/src/main/java/net/momirealms/craftengine/core/world/chunk/client/ClientChunk.java
+++ b/core/src/main/java/net/momirealms/craftengine/core/world/chunk/client/ClientChunk.java
@@ -22,6 +22,7 @@ public class ClientChunk {
     public boolean isOccluding(int x, int y, int z) {
         if (this.sections == null) return false;
         int index = sectionIndex(SectionPos.blockToSectionCoord(y));
+        if (index < 0 || index >= this.sections.length) return false;
         ClientSection section = this.sections[index];
         if (section == null) return false;
         return section.isOccluding((y & 15) << 8 | (z & 15) << 4 | x & 15);
@@ -30,6 +31,7 @@ public class ClientChunk {
     public void setOccluding(int x, int y, int z, boolean occluding) {
         if (this.sections == null) return;
         int index = sectionIndex(SectionPos.blockToSectionCoord(y));
+        if (index < 0 || index >= this.sections.length) return;
         ClientSection section = this.sections[index];
         if (section == null) return;
         section.setOccluding((y & 15) << 8 | (z & 15) << 4 | x & 15, occluding);
diff --git a/gradle.properties b/gradle.properties
index 496c67425..bf950c905 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,7 +1,7 @@
 org.gradle.jvmargs=-Xmx1G
 
 # Project settings
-project_version=0.0.65.17
+project_version=0.0.65.18
 config_version=60
 lang_version=43
 project_group=net.momirealms