diff --git a/CHANGELOG.md b/CHANGELOG.md
index 40a83931b3..0d9640f35e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,5 @@
 # Table of contents
-- [Release Candidate 31 (TBD)](#release-candidate-31-tbd)
+- [Release Candidate 31 (14 Mar 2022)](#release-candidate-31-14-mar-2022)
 - [Release Candidate 30 (31 Dec 2021)](#release-candidate-30-31-dec-2021)
 - [Release Candidate 29 (07 Nov 2021)](#release-candidate-29-07-nov-2021)
 - [Release Candidate 28 (06 Sep 2021)](#release-candidate-28-06-sep-2021)
@@ -31,7 +31,7 @@
 - [Release Candidate 2 (29 Sep 2019)](#release-candidate-2-29-sep-2019)
 - [Release Candidate 1 (26 Sep 2019)](#release-candidate-1-26-sep-2019)
 
-## Release Candidate 31 (TBD)
+## Release Candidate 31 (14 Mar 2022)
 
 #### Additions
 * Added Armored Jetpack
@@ -49,6 +49,7 @@
 * You can now pick up Slimefun blocks in creative mode using the middle mouse button
 * `/sf search` no longer shows items in hidden item groups (can be overidden by a config setting)
 * Fluid Pumps can now fill bottles with water
+* (API) Added Shulker boxes to `ColoredMaterial` enum
 
 #### Changes
 * (API) `BiomeMapParser` is now `public`
diff --git a/src/main/java/io/github/thebusybiscuit/slimefun4/core/guide/options/SlimefunGuideOption.java b/src/main/java/io/github/thebusybiscuit/slimefun4/core/guide/options/SlimefunGuideOption.java
index a1318fedfb..1caeb02826 100644
--- a/src/main/java/io/github/thebusybiscuit/slimefun4/core/guide/options/SlimefunGuideOption.java
+++ b/src/main/java/io/github/thebusybiscuit/slimefun4/core/guide/options/SlimefunGuideOption.java
@@ -2,6 +2,8 @@
 
 import java.util.Optional;
 
+import javax.annotation.Nonnull;
+
 import org.bukkit.Keyed;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
@@ -24,6 +26,7 @@ public interface SlimefunGuideOption<T> extends Keyed {
      * 
      * @return The registering {@link SlimefunAddon}
      */
+    @Nonnull
     SlimefunAddon getAddon();
 
     Optional<ItemStack> getDisplayItem(Player p, ItemStack guide);