diff --git a/eos/effects/modulebonusomnidirectionaltrackingenhancer.py b/eos/effects/modulebonusomnidirectionaltrackingenhancer.py
index 584de14bf..02e7c243b 100644
--- a/eos/effects/modulebonusomnidirectionaltrackingenhancer.py
+++ b/eos/effects/modulebonusomnidirectionaltrackingenhancer.py
@@ -4,16 +4,16 @@
 # Modules from group: Drone Tracking Enhancer (10 of 10)
 type = "passive"
 def handler(fit, src, context):
-    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackMissileExplosionRadius", src.getModifiedItemAttr("aoeCloudSizeBonus"))
-    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackMissileRangeOptimal", src.getModifiedItemAttr("maxRangeBonus"))
-    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackTurretRangeFalloff", src.getModifiedItemAttr("falloffBonus"))
-    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityMissilesExplosionRadius", src.getModifiedItemAttr("aoeCloudSizeBonus"))
+    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackMissileExplosionRadius", src.getModifiedItemAttr("aoeCloudSizeBonus"), stackingPenalties=True))
+    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackMissileRangeOptimal", src.getModifiedItemAttr("maxRangeBonus"), stackingPenalties=True))
+    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackTurretRangeFalloff", src.getModifiedItemAttr("falloffBonus"), stackingPenalties=True))
+    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityMissilesExplosionRadius", src.getModifiedItemAttr("aoeCloudSizeBonus"), stackingPenalties=True))
     fit.drones.filteredItemBoost(lambda mod: mod.item.requiresSkill("Drones"), "falloff", src.getModifiedItemAttr("falloffBonus"), stackingPenalties=True)
-    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackMissileRangeFalloff", src.getModifiedItemAttr("falloffBonus"))
-    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackTurretTrackingSpeed", src.getModifiedItemAttr("trackingSpeedBonus"))
+    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackMissileRangeFalloff", src.getModifiedItemAttr("falloffBonus"), stackingPenalties=True))
+    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackTurretTrackingSpeed", src.getModifiedItemAttr("trackingSpeedBonus"), stackingPenalties=True))
     fit.drones.filteredItemBoost(lambda mod: mod.item.requiresSkill("Drones"), "maxRange", src.getModifiedItemAttr("maxRangeBonus"), stackingPenalties=True)
     fit.drones.filteredItemBoost(lambda mod: mod.item.requiresSkill("Drones"), "trackingSpeed", src.getModifiedItemAttr("trackingSpeedBonus"), stackingPenalties=True)
-    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackTurretRangeOptimal", src.getModifiedItemAttr("maxRangeBonus"))
-    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityMissilesExplosionVelocity", src.getModifiedItemAttr("aoeVelocityBonus"))
-    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackMissileExplosionVelocity", src.getModifiedItemAttr("aoeVelocityBonus"))
-    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityMissilesRange", src.getModifiedItemAttr("maxRangeBonus"))
+    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackTurretRangeOptimal", src.getModifiedItemAttr("maxRangeBonus"), stackingPenalties=True))
+    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityMissilesExplosionVelocity", src.getModifiedItemAttr("aoeVelocityBonus"), stackingPenalties=True))
+    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityAttackMissileExplosionVelocity", src.getModifiedItemAttr("aoeVelocityBonus"), stackingPenalties=True))
+    fit.fighters.filteredItemBoost(lambda mod: mod.item.requiresSkill("Fighters"), "fighterAbilityMissilesRange", src.getModifiedItemAttr("maxRangeBonus"), stackingPenalties=True))
diff --git a/gui/builtinViews/fittingView.py b/gui/builtinViews/fittingView.py
index 8d6ed961b..15615d3bc 100644
--- a/gui/builtinViews/fittingView.py
+++ b/gui/builtinViews/fittingView.py
@@ -557,7 +557,7 @@ class FittingView(d.Display):
                      5: ''}
 
     def slotColour(self, slot):
-        return self.slotColourMap[slot] or self.GetBackgroundColour()
+        return self.slotColourMap.get(slot) or self.GetBackgroundColour()
 
     def refresh(self, stuff):
         '''