diff --git a/service/port.py b/service/port.py
index bf0699eb3..e4b40d2d6 100644
--- a/service/port.py
+++ b/service/port.py
@@ -615,10 +615,14 @@ class Port(object):
     @staticmethod
     def exportDna(fit):
         dna = str(fit.shipID)
+        subsystems = []  # EVE cares which order you put these in
         mods = OrderedDict()
         charges = OrderedDict()
         for mod in fit.modules:
             if not mod.isEmpty:
+                if mod.slot == Slot.SUBSYSTEM:
+                    subsystems.append(mod)
+                    continue
                 if not mod.itemID in mods:
                     mods[mod.itemID] = 0
                 mods[mod.itemID] += 1
@@ -632,6 +636,9 @@ class Port(object):
         for mod in mods:
             dna += ":{0};{1}".format(mod, mods[mod])
 
+        for subsystem in sorted(subsystems, key=lambda mod: mod.getModifiedItemAttr("subSystemSlot")):
+            dna += ":{0};1".format(subsystem.itemID)
+        
         for drone in fit.drones:
             dna += ":{0};{1}".format(drone.itemID, drone.amount)
 
@@ -674,10 +681,17 @@ class Port(object):
                     continue
 
                 slot = module.slot
-                if not slot in slotNum:
-                    slotNum[slot] = 0
-                slotId = slotNum[slot]
-                slotNum[slot] += 1
+
+                if slot == Slot.SUBSYSTEM:
+                    # Order of subsystem matters based on this attr. See GH issue #130
+                    slotId = module.getModifiedItemAttr("subSystemSlot") - 124
+                else:
+                    if not slot in slotNum:
+                        slotNum[slot] = 0
+                
+                    slotId = slotNum[slot]
+                    slotNum[slot] += 1
+                    
                 hardware = doc.createElement("hardware")
                 hardware.setAttribute("type", module.item.name)
                 slotName = Slot.getName(slot).lower()