diff --git a/paper-api/src/main/java/org/bukkit/metadata/MetadataStore.java b/paper-api/src/main/java/org/bukkit/metadata/MetadataStore.java
index 0adfa7a006..273a273f1a 100644
--- a/paper-api/src/main/java/org/bukkit/metadata/MetadataStore.java
+++ b/paper-api/src/main/java/org/bukkit/metadata/MetadataStore.java
@@ -11,6 +11,7 @@ public interface MetadataStore<T> {
      * @param subject The object receiving the metadata.
      * @param metadataKey A unique key to identify this metadata.
      * @param newMetadataValue The metadata value to apply.
+     * @throws IllegalArgumentException If value is null, or the owning plugin is null
      */
     public void setMetadata(T subject, String metadataKey, MetadataValue newMetadataValue);
 
@@ -39,6 +40,7 @@ public interface MetadataStore<T> {
      * @param subject the object to remove the metadata from.
      * @param metadataKey the unique metadata key identifying the metadata to remove.
      * @param owningPlugin the plugin attempting to remove a metadata item.
+     * @throws IllegalArgumentException If plugin is null
      */
     public void removeMetadata(T subject, String metadataKey, Plugin owningPlugin);
 
@@ -47,6 +49,7 @@ public interface MetadataStore<T> {
      * each invalidated metadata item to be recalculated the next time it is accessed.
      *
      * @param owningPlugin the plugin requesting the invalidation.
+     * @throws IllegalArgumentException If plugin is null
      */
     public void invalidateAll(Plugin owningPlugin);
 }
diff --git a/paper-api/src/main/java/org/bukkit/metadata/MetadataStoreBase.java b/paper-api/src/main/java/org/bukkit/metadata/MetadataStoreBase.java
index 9bbe364706..7febbd43e3 100644
--- a/paper-api/src/main/java/org/bukkit/metadata/MetadataStoreBase.java
+++ b/paper-api/src/main/java/org/bukkit/metadata/MetadataStoreBase.java
@@ -1,5 +1,6 @@
 package org.bukkit.metadata;
 
+import org.apache.commons.lang.Validate;
 import org.bukkit.plugin.Plugin;
 
 import java.util.*;
@@ -22,8 +23,11 @@ public abstract class MetadataStoreBase<T> {
      * @param metadataKey      A unique key to identify this metadata.
      * @param newMetadataValue The metadata value to apply.
      * @see MetadataStore#setMetadata(Object, String, MetadataValue)
+     * @throws IllegalArgumentException If value is null, or the owning plugin is null
      */
     public synchronized void setMetadata(T subject, String metadataKey, MetadataValue newMetadataValue) {
+        Validate.notNull(newMetadataValue, "Value cannot be null");
+        Validate.notNull(newMetadataValue.getOwningPlugin(), "Plugin cannot be null");
         String key = cachedDisambiguate(subject, metadataKey);
         if (!metadataMap.containsKey(key)) {
             metadataMap.put(key, new ArrayList<MetadataValue>());
@@ -78,8 +82,10 @@ public abstract class MetadataStoreBase<T> {
      * @param metadataKey  the unique metadata key identifying the metadata to remove.
      * @param owningPlugin the plugin attempting to remove a metadata item.
      * @see MetadataStore#removeMetadata(Object, String, org.bukkit.plugin.Plugin)
+     * @throws IllegalArgumentException If plugin is null
      */
     public synchronized void removeMetadata(T subject, String metadataKey, Plugin owningPlugin) {
+        Validate.notNull(owningPlugin, "Plugin cannot be null");
         String key = cachedDisambiguate(subject, metadataKey);
         List<MetadataValue> metadataList = metadataMap.get(key);
         if (metadataList == null) return;
@@ -99,12 +105,10 @@ public abstract class MetadataStoreBase<T> {
      *
      * @param owningPlugin the plugin requesting the invalidation.
      * @see MetadataStore#invalidateAll(org.bukkit.plugin.Plugin)
+     * @throws IllegalArgumentException If plugin is null
      */
     public synchronized void invalidateAll(Plugin owningPlugin) {
-        if (owningPlugin == null) {
-            throw new IllegalArgumentException("owningPlugin cannot be null");
-        }
-
+        Validate.notNull(owningPlugin, "Plugin cannot be null");
         for (List<MetadataValue> values : metadataMap.values()) {
             for (MetadataValue value : values) {
                 if (value.getOwningPlugin().equals(owningPlugin)) {
diff --git a/paper-api/src/main/java/org/bukkit/metadata/MetadataValue.java b/paper-api/src/main/java/org/bukkit/metadata/MetadataValue.java
index 761d1ac959..deec40fb35 100644
--- a/paper-api/src/main/java/org/bukkit/metadata/MetadataValue.java
+++ b/paper-api/src/main/java/org/bukkit/metadata/MetadataValue.java
@@ -62,7 +62,7 @@ public interface MetadataValue {
     /**
      * Returns the {@link Plugin} that created this metadata item.
      *
-     * @return the plugin that owns this metadata value.
+     * @return the plugin that owns this metadata value. This should never be null.
      */
     public Plugin getOwningPlugin();
 
diff --git a/paper-api/src/main/java/org/bukkit/metadata/Metadatable.java b/paper-api/src/main/java/org/bukkit/metadata/Metadatable.java
index 956a1960fb..41711be805 100644
--- a/paper-api/src/main/java/org/bukkit/metadata/Metadatable.java
+++ b/paper-api/src/main/java/org/bukkit/metadata/Metadatable.java
@@ -13,6 +13,7 @@ public interface Metadatable {
      *
      * @param metadataKey A unique key to identify this metadata.
      * @param newMetadataValue The metadata value to apply.
+     * @throws IllegalArgumentException If value is null, or the owning plugin is null
      */
     public void setMetadata(String metadataKey, MetadataValue newMetadataValue);
 
@@ -37,6 +38,7 @@ public interface Metadatable {
      *
      * @param metadataKey the unique metadata key identifying the metadata to remove.
      * @param owningPlugin This plugin's metadata value will be removed. All other values will be left untouched.
+     * @throws IllegalArgumentException If plugin is null
      */
     public void removeMetadata(String metadataKey, Plugin owningPlugin);
 }