diff --git a/eco-api/src/main/java/com/willfp/eco/core/gui/menu/MenuBuilder.java b/eco-api/src/main/java/com/willfp/eco/core/gui/menu/MenuBuilder.java
index b43dd472..a56628f0 100644
--- a/eco-api/src/main/java/com/willfp/eco/core/gui/menu/MenuBuilder.java
+++ b/eco-api/src/main/java/com/willfp/eco/core/gui/menu/MenuBuilder.java
@@ -195,6 +195,16 @@ public interface MenuBuilder extends PageBuilder {
         return this;
     }
 
+    /**
+     * Add an action to run on build.
+     *
+     * @param action The action.
+     * @return The builder.
+     */
+    default MenuBuilder onBuild(@NotNull Consumer<Menu> action) {
+        return this;
+    }
+
     /**
      * Build the menu.
      *
diff --git a/eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/menu/EcoMenuBuilder.kt b/eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/menu/EcoMenuBuilder.kt
index 4cc41ae3..f4b51ed1 100644
--- a/eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/menu/EcoMenuBuilder.kt
+++ b/eco-core/core-backend/src/main/kotlin/com/willfp/eco/internal/gui/menu/EcoMenuBuilder.kt
@@ -22,6 +22,7 @@ class EcoMenuBuilder(
     private val onOpen = mutableListOf<OpenHandler>()
     private val onRender = mutableListOf<(Player, Menu) -> Unit>()
     private val menuEventHandlers = mutableListOf<MenuEventHandler<*>>()
+    private val onBuild = mutableListOf<(Menu) -> Unit>()
     private var allowsChangingHeldItem = false
 
     override fun getRows() = rows
@@ -80,6 +81,11 @@ class EcoMenuBuilder(
         return this
     }
 
+    override fun onBuild(action: Consumer<Menu>): MenuBuilder {
+        onBuild += { action.accept(it) }
+        return this
+    }
+
     override fun allowChangingHeldItem(): MenuBuilder {
         allowsChangingHeldItem = true
         return this
@@ -122,7 +128,7 @@ class EcoMenuBuilder(
             }
         }
 
-        return EcoMenu(
+        val menu = EcoMenu(
             rows,
             columns,
             layeredComponents,
@@ -133,5 +139,9 @@ class EcoMenuBuilder(
             menuEventHandlers,
             allowsChangingHeldItem
         )
+
+        onBuild.forEach { it(menu) } // Run on build functions.
+
+        return menu
     }
 }