diff --git a/pokedex/data/csv/types.csv b/pokedex/data/csv/types.csv
index 7676b5c..5c0457a 100644
--- a/pokedex/data/csv/types.csv
+++ b/pokedex/data/csv/types.csv
@@ -16,5 +16,5 @@ id,name,abbreviation,generation_id,damage_class_id
 15,Ice,ICE,1,3
 16,Dragon,DRG,1,3
 17,Dark,DAR,2,3
-10001,???,???,2,1
-10002,Shadow,SHA,3,1
+10001,???,???,2,
+10002,Shadow,SHA,3,
diff --git a/pokedex/db/tables.py b/pokedex/db/tables.py
index 460cfc2..4375c07 100644
--- a/pokedex/db/tables.py
+++ b/pokedex/db/tables.py
@@ -1264,8 +1264,8 @@ class Type(TableBase):
         info=dict(description=u"An arbitrary 3-letter abbreviation of this type.", format='plaintext'))  # XXX: Or is it not arbitrary?
     generation_id = Column(Integer, ForeignKey('generations.id'), nullable=False,
         info=dict(description=u"The ID of the generation this type first appeared in."))
-    damage_class_id = Column(Integer, ForeignKey('move_damage_classes.id'), nullable=False,
-        info=dict(description=u"The ID of the damage class this type's moves had before Generation IV."))
+    damage_class_id = Column(Integer, ForeignKey('move_damage_classes.id'), nullable=True,
+        info=dict(description=u"The ID of the damage class this type's moves had before Generation IV, null if not applicable (e.g. ???)."))
 
 class TypeName(TableBase):
     u"""An official non-English name of an elemental type."""