diff --git a/eos/effects/miningdroneoperationminingamountbonuspostpercentminingdroneamountpercentchar.py b/eos/effects/miningdroneoperationminingamountbonuspostpercentminingdroneamountpercentchar.py
index c9074971e..ebad7da0e 100644
--- a/eos/effects/miningdroneoperationminingamountbonuspostpercentminingdroneamountpercentchar.py
+++ b/eos/effects/miningdroneoperationminingamountbonuspostpercentminingdroneamountpercentchar.py
@@ -7,5 +7,4 @@ type = "passive"
 def handler(fit, container, context):
     level = container.level if "skill" in context else 1
     fit.drones.filteredItemBoost(lambda drone: drone.item.group.name == "Mining Drone",
-                                 "miningAmount", container.getModifiedItemAttr("miningAmountBonus") * level,
-                                 stackingPenalties = "skill" not in context)
+                                 "miningAmount", container.getModifiedItemAttr("miningAmountBonus") * level)