diff --git a/bukkit/src/main/java/net/momirealms/craftengine/bukkit/block/BukkitCustomBlock.java b/bukkit/src/main/java/net/momirealms/craftengine/bukkit/block/BukkitCustomBlock.java
index df0f1a768..af70dad99 100644
--- a/bukkit/src/main/java/net/momirealms/craftengine/bukkit/block/BukkitCustomBlock.java
+++ b/bukkit/src/main/java/net/momirealms/craftengine/bukkit/block/BukkitCustomBlock.java
@@ -130,8 +130,8 @@ public final class BukkitCustomBlock extends AbstractCustomBlock {
                 CoreReflections.field$BlockBehaviour$explosionResistance.set(nmsBlock, settings.resistance());
                 CoreReflections.field$BlockBehaviour$soundType.set(nmsBlock, SoundUtils.toSoundType(settings.sounds()));
                 // 1.21.2以前要在init cache之前设定 isConditionallyFullOpaque
+                boolean isConditionallyFullOpaque = canOcclude & useShapeForLightOcclusion;
                 if (!VersionHelper.isOrAbove1_21_2()) {
-                    boolean isConditionallyFullOpaque = canOcclude & useShapeForLightOcclusion;
                     CoreReflections.field$BlockStateBase$isConditionallyFullOpaque.set(nmsState, isConditionallyFullOpaque);
                 }
                 // init cache
@@ -162,6 +162,9 @@ public final class BukkitCustomBlock extends AbstractCustomBlock {
                     } else {
                         CoreReflections.field$BlockStateBase$Cache$propagatesSkylightDown.set(cache, CoreReflections.field$BlockStateBase$Cache$propagatesSkylightDown.getBoolean(CoreReflections.field$BlockStateBase$cache.get(immutableBlockState.vanillaBlockState().handle())));
                     }
+                    if (!isConditionallyFullOpaque) {
+                        CoreReflections.field$BlockStateBase$opacityIfCached.set(nmsState, blockLight);
+                    }
                 }
                 // set fluid later
                 if (settings.fluidState()) {
diff --git a/bukkit/src/main/java/net/momirealms/craftengine/bukkit/plugin/reflection/minecraft/CoreReflections.java b/bukkit/src/main/java/net/momirealms/craftengine/bukkit/plugin/reflection/minecraft/CoreReflections.java
index ee3439b35..561c4a356 100644
--- a/bukkit/src/main/java/net/momirealms/craftengine/bukkit/plugin/reflection/minecraft/CoreReflections.java
+++ b/bukkit/src/main/java/net/momirealms/craftengine/bukkit/plugin/reflection/minecraft/CoreReflections.java
@@ -1328,6 +1328,10 @@ public final class CoreReflections {
     public static final Field field$BlockStateBase$lightBlock =
             ReflectionUtils.getInstanceDeclaredField(clazz$BlockStateBase, int.class, 1);
 
+    // 1.20-1.21.1
+    public static final Field field$BlockStateBase$opacityIfCached =
+            ReflectionUtils.getInstanceDeclaredField(clazz$BlockStateBase, int.class, 1);
+
     public static final Class<?> clazz$AABB = requireNonNull(
             BukkitReflectionUtils.findReobfOrMojmapClass(
                     "world.phys.AxisAlignedBB",