diff --git a/src/main/java/com/Acrobot/Breeze/Utils/BlockUtil.java b/src/main/java/com/Acrobot/Breeze/Utils/BlockUtil.java
index 2d9ead651..299481485 100644
--- a/src/main/java/com/Acrobot/Breeze/Utils/BlockUtil.java
+++ b/src/main/java/com/Acrobot/Breeze/Utils/BlockUtil.java
@@ -18,6 +18,7 @@
 public class BlockUtil {
 
     private static EnumSet<Material> SIGNS = EnumSet.noneOf(Material.class);
+    private static EnumSet<Material> SHULKER_BOXES = EnumSet.noneOf(Material.class);
     private static EnumSet<Material> CONTAINERS = EnumSet.noneOf(Material.class);
     static {
         SIGNS.add(Material.ACACIA_SIGN);
@@ -33,26 +34,28 @@ public class BlockUtil {
         SIGNS.add(Material.SPRUCE_SIGN);
         SIGNS.add(Material.SPRUCE_WALL_SIGN);
 
+        SHULKER_BOXES.add(Material.SHULKER_BOX);
+        SHULKER_BOXES.add(Material.BLACK_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.BLUE_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.BROWN_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.CYAN_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.GRAY_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.GREEN_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.LIGHT_BLUE_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.LIGHT_GRAY_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.LIME_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.MAGENTA_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.ORANGE_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.PINK_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.PURPLE_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.RED_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.WHITE_SHULKER_BOX);
+        SHULKER_BOXES.add(Material.YELLOW_SHULKER_BOX);
+
         CONTAINERS.add(Material.CHEST);
         CONTAINERS.add(Material.TRAPPED_CHEST);
         CONTAINERS.add(Material.BARREL);
-        CONTAINERS.add(Material.SHULKER_BOX);
-        CONTAINERS.add(Material.BLACK_SHULKER_BOX);
-        CONTAINERS.add(Material.BLUE_SHULKER_BOX);
-        CONTAINERS.add(Material.BROWN_SHULKER_BOX);
-        CONTAINERS.add(Material.CYAN_SHULKER_BOX);
-        CONTAINERS.add(Material.GRAY_SHULKER_BOX);
-        CONTAINERS.add(Material.GREEN_SHULKER_BOX);
-        CONTAINERS.add(Material.LIGHT_BLUE_SHULKER_BOX);
-        CONTAINERS.add(Material.LIGHT_GRAY_SHULKER_BOX);
-        CONTAINERS.add(Material.LIME_SHULKER_BOX);
-        CONTAINERS.add(Material.MAGENTA_SHULKER_BOX);
-        CONTAINERS.add(Material.ORANGE_SHULKER_BOX);
-        CONTAINERS.add(Material.PINK_SHULKER_BOX);
-        CONTAINERS.add(Material.PURPLE_SHULKER_BOX);
-        CONTAINERS.add(Material.RED_SHULKER_BOX);
-        CONTAINERS.add(Material.WHITE_SHULKER_BOX);
-        CONTAINERS.add(Material.YELLOW_SHULKER_BOX);
+        CONTAINERS.addAll(SHULKER_BOXES);
     }
 
     /**
@@ -88,6 +91,17 @@ public static boolean isChest(Block block) {
         return block != null && CONTAINERS.contains(block.getType());
     }
 
+    /**
+     * Checks if the material is a shulker box
+     *
+     * @param type
+     *            Material to check
+     * @return Is this material a shulker box?
+     */
+    public static boolean isShulkerBox(Material type) {
+        return SHULKER_BOXES.contains(type);
+    }
+
     /**
      * Gets the block to which the sign is attached
      *
diff --git a/src/main/java/com/Acrobot/ChestShop/Listeners/Player/PlayerInteract.java b/src/main/java/com/Acrobot/ChestShop/Listeners/Player/PlayerInteract.java
index 995b5073c..d61c759df 100644
--- a/src/main/java/com/Acrobot/ChestShop/Listeners/Player/PlayerInteract.java
+++ b/src/main/java/com/Acrobot/ChestShop/Listeners/Player/PlayerInteract.java
@@ -35,6 +35,7 @@
 import org.bukkit.OfflinePlayer;
 import org.bukkit.block.Block;
 import org.bukkit.block.Container;
+import org.bukkit.block.ShulkerBox;
 import org.bukkit.block.Sign;
 import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
@@ -138,6 +139,12 @@ private static void showShopInfo(Player player, Sign sign) {
             if (!ChestShopSign.isAdminShop(sign)) {
                 Container chest = uBlock.findConnectedChest(sign);
                 if (chest != null) {
+                    // do not allow shulker boxes inside of shulker boxes
+                    if (chest instanceof ShulkerBox && BlockUtil.isShulkerBox(item.getType())) {
+                        player.sendMessage(Messages.prefix(Messages.INVALID_SHOP_DETECTED));
+                        return;
+                    }
+
                     player.sendMessage(Messages.prefix(Messages.SHOP_INFO));
                     String prices = sign.getLine(PRICE_LINE);
                     Inventory inventory = chest.getInventory();
@@ -181,6 +188,11 @@ private static PreTransactionEvent preparePreTransactionEvent(Sign sign, Player
             player.sendMessage(Messages.prefix(Messages.INVALID_SHOP_DETECTED));
             return null;
         }
+        // do not allow shulker boxes inside of shulker boxes
+        if (!ChestShopSign.isAdminShop(sign) && chest instanceof ShulkerBox && BlockUtil.isShulkerBox(item.getType())) {
+            player.sendMessage(Messages.prefix(Messages.INVALID_SHOP_DETECTED));
+            return null;
+        }
 
         int amount = Integer.parseInt(quantity);