diff --git a/eco-api/src/main/java/com/willfp/eco/core/recipe/parts/ModifiedTestableItem.java b/eco-api/src/main/java/com/willfp/eco/core/recipe/parts/ModifiedTestableItem.java
index 6ee6941a1..ef237cb8a 100644
--- a/eco-api/src/main/java/com/willfp/eco/core/recipe/parts/ModifiedTestableItem.java
+++ b/eco-api/src/main/java/com/willfp/eco/core/recipe/parts/ModifiedTestableItem.java
@@ -8,6 +8,11 @@
 
 import java.util.function.Predicate;
 
+/**
+ * Existing testable items with an extra filter.
+ *
+ * @see com.willfp.eco.core.items.CustomItem
+ */
 public class ModifiedTestableItem implements TestableItem {
     /**
      * The item.