Stackable Shulkers Fix

Stackable Shulkers Fix

Fixes issues with stackable shulker boxes in Carpet on 1.20.5+

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19.6K Downloads
fabricutility
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About this Mod

Stackable shulkers fix

A simple addon to the Carpet mod that fixes the 1.20.5+ behaviour of stacked shulker boxes to be the same as in older versions, as well as some optional features.

Features

NOTE
Features marked as intrusive are modifying the standard behaviour in their default state. This is done to maintain compatibility with older versions of the mod.

Fixed hopper transfers

Prevents hoppers from stacking shulker boxes, even if the max count is >1.
Setting this rule to false enables the functionality of this mod by preventing shulkers from being stacked by hoppers.

  • Name: hopperShulkerStacking
  • Type: boolean
  • Default: false
  • Categories: shulkerfix, bugfix, intrusive
  • Since: 1.5

Fixed comparator output

Changes how stacked shulker boxes affect comparator output:

  1. true: Shulkers have signal strength of unstackable items, allowing output up to 897 (AKA OSS/HSS);
  2. false: Shulkers have signal strength of stackable items, reaching 15 when all slots are full (hoppers won't be able to fill over SS1);
  3. capped: Shulkers have signal strength of unstackable items, but the resulting output is capped at 15. This implementation preserves overstacked item filters.
  4. normalized: Any amount of shulkers in a slot is counted as a single unstackable item. This limits the output to signal strength 15 and patches overstacked item filters.
  • Name: overstackedShulkerSignalStrength
  • Type: string
  • Default: true
  • Options: true, false, capped, normalized
  • Categories: shulkerfix, bugfix, intrusive
  • Since: 1.7.1

Legacy shulker item merging

Reintroduces the logic for merging shulker box items before 1.20.5.
The implementation allows partial item merging
(normally the game doesn't merge item stacks if the total amount is more than the max size)
and resets the entity age, allowing faster merging.
(Both were bugs in Carpet, but no one complained, so now we're reintroducing the bugs huh)

  • Name: legacyShulkerItemMerging
  • Type: boolean
  • Default: false
  • Categories: shulkerfix, experimental
  • Since: 1.6

Hopper collection

Makes hoppers pick up one shulker at a time from an entity stack.
Note that this has a risk of breaking contraptions.

  • Name: hopperCollectSingleShulkers
  • Type: boolean
  • Default: false
  • Categories: shulkerfix, feature, experimental
  • Since: 1.5

Hopper minecart collection

Makes minecarts pick up one shulker at a time from an entity stack.
Note that this has a risk of breaking contraptions.

  • Name: minecartCollectSingleShulkers
  • Type: boolean
  • Default: false
  • Categories: shulkerfix, feature, experimental
  • Since: 1.5

Minecart slowdown

Disables the additional slowdown caused by overstacked minecarts.
The implementation makes shulker boxes count as 64-stackable when calculating the minecart slowdown. However if overstackedShulkerSignalStrength is enabled, reading the fill level will still output the overstacked value.
Setting this rule to false enables the functionality of this mod by removing the additional slowdown.

  • Name: overstackedMinecartSlowdown
  • Type: boolean
  • Default: true
  • Categories: shulkerfix, feature, experimental
  • Since: 1.5

Client count fix

Fixes Carpet issue #1899,
where vanilla clients see stacked shulker boxes as single items inside containers.

  • Name: clientShulkerSync
  • Type: boolean
  • Default: false
  • Categories: shulkerfix, bugfix, experimental
  • Since: 1.4

Available Versions

ShulkerFix 1.7.7 for 26.1release
MC 26.1, 26.1.1, 26.1.2fabric
April 2, 2026
ShulkerFix 1.7.7 for 1.21.11release
MC 1.21.11fabric
December 17, 2025
ShulkerFix 1.7.6 for 1.21.10release
MC 1.21.9, 1.21.10fabric
October 27, 2025
ShulkerFix 1.7.4 for 1.21.5+release
MC 1.21.5, 1.21.6, 1.21.7, 1.21.8fabric
June 21, 2025
ShulkerFix 1.7.4 for 1.20.5-1.21.4release
MC 1.20.5, 1.20.6, 1.21, 1.21.1, 1.21.2, 1.21.3, 1.21.4fabric
June 21, 2025

How to Install Stackable Shulkers Fix on Your Server

1

Order Server

Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).

2

Set fabric Loader

In the panel under "Egg", select the fabric loader and matching Minecraft version (26.1.2).

3

Install Mod

Open the mod browser in the dashboard and search for "Stackable Shulkers Fix". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.

Compatibility

Mod Loaders

fabric

Minecraft Versions

26.1.2, 26.1.1, 26.1 (+14 more)

Server-side

Required

Recommended RAM

4 GB(min. 3 GB)

Frequently Asked Questions

Stackable Shulkers Fix server crashes on startup – what to do?

Most common cause: wrong fabric version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (26.1.2). You can switch loaders with one click in the panel.

Is Stackable Shulkers Fix compatible with fabric?

Stackable Shulkers Fix officially supports fabric for Minecraft 26.1.2, 26.1.1, 26.1. The Mado dashboard automatically detects incompatible loader combinations.

Server lagging with Stackable Shulkers Fix – how to optimize performance?

Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if Stackable Shulkers Fix consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.

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Install Stackable Shulkers Fix with just one click on your server.

Recommended RAM
4 GBab €8/mo
Min. 3 GB | +1 GB pro 8 Spieler
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NVMe SSD Storage
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Details

License
MIT License
Server-side
Required

Supported Versions

26.1.226.1.126.11.21.111.21.101.21.91.21.81.21.71.21.61.21.5+7 more