diff --git a/leaves-server/src/main/java/org/leavesmc/leaves/LeavesConfig.java b/leaves-server/src/main/java/org/leavesmc/leaves/LeavesConfig.java
index ab56f8cd..323c9a27 100644
--- a/leaves-server/src/main/java/org/leavesmc/leaves/LeavesConfig.java
+++ b/leaves-server/src/main/java/org/leavesmc/leaves/LeavesConfig.java
@@ -23,6 +23,7 @@ import org.leavesmc.leaves.config.annotations.GlobalConfig;
 import org.leavesmc.leaves.config.annotations.GlobalConfigCategory;
 import org.leavesmc.leaves.config.annotations.TransferConfig;
 import org.leavesmc.leaves.config.api.ConfigTransformer;
+import org.leavesmc.leaves.config.api.ConfigValidator;
 import org.leavesmc.leaves.config.api.impl.ConfigValidatorImpl.BooleanConfigValidator;
 import org.leavesmc.leaves.config.api.impl.ConfigValidatorImpl.DoubleConfigValidator;
 import org.leavesmc.leaves.config.api.impl.ConfigValidatorImpl.EnumConfigValidator;
@@ -478,17 +479,60 @@ public final class LeavesConfig {
         @GlobalConfigCategory("shulker-box")
         public static class ShulkerBoxConfig {
 
-            public int shulkerBoxStackSize = 1;
-
             @TransferConfig("modify.stackable-shulker-boxes")
             @GlobalConfig(value = "stackable-shulker-boxes", validator = StackableShulkerValidator.class)
-            private String stackableShulkerBoxes = "false";
+            public int stackableShulkerBoxes = 1;
+
+            private static class StackableShulkerValidator implements ConfigValidator<Integer> {
 
-            private static class StackableShulkerValidator extends StringConfigValidator {
                 @Override
-                public void verify(String old, String value) throws IllegalArgumentException {
-                    String realValue = MathUtils.isNumeric(value) ? value : value.equals("true") ? "2" : "1";
-                    LeavesConfig.modify.shulkerBox.shulkerBoxStackSize = Integer.parseInt(realValue);
+                public Integer loadConvert(Object value) throws IllegalArgumentException {
+                    switch (value) {
+                        case String stringValue -> {
+                            if (stringValue.equals("true")) {
+                                return 2;
+                            } else if (!MathUtils.isNumeric(stringValue)) {
+                                return 1;
+                            } else {
+                                return Integer.parseInt(stringValue);
+                            }
+                        }
+                        case Integer integerValue -> {
+                            return integerValue;
+                        }
+                        case Boolean boolValue -> {
+                            return boolValue ? 2 : 1;
+                        }
+                        case null, default -> throw new IllegalArgumentException("stackable-shulker-boxes need string or integer or boolean");
+                    }
+                }
+
+                @Override
+                public Object saveConvert(Integer value) {
+                    if (value == 1) {
+                        return false;
+                    } else if (value == 2) {
+                        return true;
+                    } else {
+                        return value;
+                    }
+                }
+
+                @Override
+                public Integer stringConvert(String value) throws IllegalArgumentException {
+                    return loadConvert(value);
+                }
+
+                @Override
+                public void verify(Integer old, Integer value) throws IllegalArgumentException {
+                    if (value < 1 || value > 64) {
+                        throw new IllegalArgumentException("stackable-shulker-boxes need >= 1 and <= 64");
+                    }
+                }
+
+                @Override
+                public List<String> valueSuggest() {
+                    return List.of("true", "false", "64", "32");
                 }
             }
 
diff --git a/leaves-server/src/main/java/org/leavesmc/leaves/util/ItemOverstackUtils.java b/leaves-server/src/main/java/org/leavesmc/leaves/util/ItemOverstackUtils.java
index c8ebfd3c..f1b50d9a 100644
--- a/leaves-server/src/main/java/org/leavesmc/leaves/util/ItemOverstackUtils.java
+++ b/leaves-server/src/main/java/org/leavesmc/leaves/util/ItemOverstackUtils.java
@@ -131,7 +131,7 @@ public class ItemOverstackUtils {
 
         @Override
         public boolean isEnabled() {
-            return LeavesConfig.modify.shulkerBox.shulkerBoxStackSize > 1;
+            return LeavesConfig.modify.shulkerBox.stackableShulkerBoxes > 1;
         }
 
         @Override
@@ -147,8 +147,8 @@ public class ItemOverstackUtils {
             ItemStack otherStack = other.getItem();
             if (selfStack.getItem() == otherStack.getItem()
                 && shulkerBoxCheck(selfStack, otherStack)
-                && selfStack.getCount() != org.leavesmc.leaves.LeavesConfig.modify.shulkerBox.shulkerBoxStackSize) {
-                int amount = Math.min(otherStack.getCount(), org.leavesmc.leaves.LeavesConfig.modify.shulkerBox.shulkerBoxStackSize - selfStack.getCount());
+                && selfStack.getCount() != org.leavesmc.leaves.LeavesConfig.modify.shulkerBox.stackableShulkerBoxes) {
+                int amount = Math.min(otherStack.getCount(), org.leavesmc.leaves.LeavesConfig.modify.shulkerBox.stackableShulkerBoxes - selfStack.getCount());
 
                 selfStack.grow(amount);
                 self.setItem(selfStack);
@@ -171,7 +171,7 @@ public class ItemOverstackUtils {
         public int getMaxServerStackCount(ItemStack stack) {
             if (isEnabled() && stack.getItem() instanceof BlockItem bi &&
                 bi.getBlock() instanceof ShulkerBoxBlock && (LeavesConfig.modify.shulkerBox.sameNbtStackable || shulkerBoxNoItem(stack))) {
-                return LeavesConfig.modify.shulkerBox.shulkerBoxStackSize;
+                return LeavesConfig.modify.shulkerBox.stackableShulkerBoxes;
             }
             return -1;
         }