diff --git a/scripts/modtools/reaction-product-trigger.lua b/scripts/modtools/reaction-product-trigger.lua
index 9ea1b4cfd..bbeaa4d6a 100644
--- a/scripts/modtools/reaction-product-trigger.lua
+++ b/scripts/modtools/reaction-product-trigger.lua
@@ -10,6 +10,10 @@ productHooks = productHooks or {}
 
 reactionInputItems = reactionInputItems
 
+function preserveReagents()
+ reactionInputItems:resize(0)
+end
+
 eventful.enableEvent(eventful.eventType.UNLOAD,1)
 eventful.onUnload.reactionProductTrigger = function()
  productHooks = {}