diff --git a/module/models/Actor/Mob.mjs b/module/models/Actor/Mob.mjs
index e56c572..c261906 100644
--- a/module/models/Actor/Mob.mjs
+++ b/module/models/Actor/Mob.mjs
@@ -4,6 +4,7 @@ export class MobData extends foundry.abstract.TypeDataModel {
 		return {
 			dice: new fields.StringField({
 				initial: ``,
+				blank: true,
 			}),
 			bonus: new fields.NumberField({
 				initial: 0,
@@ -25,6 +26,14 @@ export class MobData extends foundry.abstract.TypeDataModel {
 				initial: ``,
 				blank: true,
 			}),
+			immune: new fields.StringField({
+				initial: ``,
+				blank: true,
+			}),
+			weak: new fields.StringField({
+				initial: ``,
+				blank: true,
+			}),
 		};
 	};
 };