diff --git a/angelsrefining/prototypes/recipes/refining-static.lua b/angelsrefining/prototypes/recipes/refining-static.lua
index 65b78ca5..faddc6c2 100644
--- a/angelsrefining/prototypes/recipes/refining-static.lua
+++ b/angelsrefining/prototypes/recipes/refining-static.lua
@@ -707,7 +707,7 @@ data:extend({
     results = {
       { type = "fluid", name = "angels-ore8-anode-sludge", amount = 60 },
       { type = "fluid", name = "water-yellow-waste", amount = 20 },
-      { type = "item", name = "slag", amount = 1 },
+      { type = "item", name = "slag", amount = 1, probability = 0.1 },
     },
     main_product = "angels-ore8-anode-sludge",
     --icon = "__angelsrefining__/graphics/icons/angels-ore6-crystal.png",
@@ -813,7 +813,7 @@ data:extend({
     results = {
       { type = "fluid", name = "angels-ore9-anode-sludge", amount = 60 },
       { type = "fluid", name = "water-yellow-waste", amount = 20 },
-      { type = "item", name = "slag", amount = 1 },
+      { type = "item", name = "slag", amount = 1, probability = 0.1 },
     },
     main_product = "angels-ore9-anode-sludge",
     --icon = "__angelsrefining__/graphics/icons/angels-ore6-crystal.png",