diff --git a/data/mods/classic_zombies/exclusions.json b/data/mods/classic_zombies/exclusions.json
index 47094a9709eef..f20e2cc360baa 100644
--- a/data/mods/classic_zombies/exclusions.json
+++ b/data/mods/classic_zombies/exclusions.json
@@ -19,14 +19,14 @@
     "type": "region_overlay",
     "regions": [ "all" ],
     "map_extras": {
-      "forest": { "chance": 20, "extras": { "mx_portal": 0, "mx_portal_in": 0, "mx_spider": 0 } },
-      "forest_thick": { "chance": 20, "extras": { "mx_portal": 0, "mx_portal_in": 0, "mx_shia": 0, "mx_spider": 0, "mx_jabberwock": 0 } },
-      "forest_water": { "chance": 20, "extras": { "mx_portal": 0, "mx_portal_in": 0, "mx_spider": 0 } },
-      "field": { "chance": 90, "extras": { "mx_portal": 0, "mx_portal_in": 0 } },
-      "road": { "chance": 75, "extras": { "mx_portal": 0, "mx_portal_in": 0 } },
-      "build": { "chance": 90, "extras": { "mx_house_spider": 0, "mx_house_wasp": 0, "mx_portal": 0, "mx_portal_in": 0 } },
+      "forest": { "extras": { "mx_portal": 0, "mx_portal_in": 0, "mx_spider": 0 } },
+      "forest_thick": { "extras": { "mx_portal": 0, "mx_portal_in": 0, "mx_shia": 0, "mx_spider": 0, "mx_jabberwock": 0 } },
+      "forest_water": { "extras": { "mx_portal": 0, "mx_portal_in": 0, "mx_spider": 0 } },
+      "field": { "extras": { "mx_portal": 0, "mx_portal_in": 0 } },
+      "road": { "extras": { "mx_portal": 0, "mx_portal_in": 0 } },
+      "build": { "extras": { "mx_house_spider": 0, "mx_house_wasp": 0, "mx_portal": 0, "mx_portal_in": 0 } },
       "marloss": { "chance": 0, "extras": { "mx_marloss_pilgrimage": 0 } },
-      "subway": { "chance": 75, "extras": { "mx_portal": 0, "mx_portal_in": 0 } }
+      "subway": { "extras": { "mx_portal": 0, "mx_portal_in": 0 } }
     }
   }
 ]