diff --git a/paper-api/src/main/java/org/bukkit/inventory/ItemStack.java b/paper-api/src/main/java/org/bukkit/inventory/ItemStack.java
index d8256fca28..c856b3ae26 100644
--- a/paper-api/src/main/java/org/bukkit/inventory/ItemStack.java
+++ b/paper-api/src/main/java/org/bukkit/inventory/ItemStack.java
@@ -174,6 +174,11 @@ public class ItemStack implements ConfigurationSerializable {
      * @return The maximum you can stack this material to.
      */
     public int getMaxStackSize() {
+        Material material = getType();
+        if (material != null) {
+            return material.getMaxStackSize();
+        }
+
         return -1;
     }