diff --git a/src/object/auto/autopowercaptor.cpp b/src/object/auto/autopowercaptor.cpp
index a292b82f..36db524c 100644
--- a/src/object/auto/autopowercaptor.cpp
+++ b/src/object/auto/autopowercaptor.cpp
@@ -269,7 +269,7 @@ void CAutoPowerCaptor::ChargeObject(float rTime)
         if (obj->Implements(ObjectInterfaceType::Slotted))
         {
             CSlottedObject* slotted = dynamic_cast<CSlottedObject*>(obj);
-            for (int slot = slotted->GetNumSlots(); slot >= 0; slot--)
+            for (int slot = slotted->GetNumSlots() - 1; slot >= 0; slot--)
             {
                 CObject *held = slotted->GetSlotContainedObject(slot);
                 if (held != nullptr && held->Implements(ObjectInterfaceType::PowerContainer))
diff --git a/src/object/auto/autopowerstation.cpp b/src/object/auto/autopowerstation.cpp
index c479f589..793f3572 100644
--- a/src/object/auto/autopowerstation.cpp
+++ b/src/object/auto/autopowerstation.cpp
@@ -134,7 +134,7 @@ bool CAutoPowerStation::EventProcess(const Event &event)
         if (vehicle != nullptr && vehicle->Implements(ObjectInterfaceType::Slotted))
         {
             CSlottedObject* slotted = dynamic_cast<CSlottedObject*>(vehicle);
-            for (int slot = slotted->GetNumSlots(); slot >= 0; slot--)
+            for (int slot = slotted->GetNumSlots() - 1; slot >= 0; slot--)
             {
                 CObject *power = slotted->GetSlotContainedObject(slot);
                 if (power != nullptr && power->Implements(ObjectInterfaceType::PowerContainer))