diff --git a/data/mods/Aftershock/mobs/aliens.json b/data/mods/Aftershock/mobs/aliens.json
index b26c970740668..31982050aeb13 100644
--- a/data/mods/Aftershock/mobs/aliens.json
+++ b/data/mods/Aftershock/mobs/aliens.json
@@ -63,7 +63,7 @@
       }
     ],
     "anger_triggers": [ "HURT", "PLAYER_WEAK", "PLAYER_CLOSE" ],
-    "flags": [ "ANIMAL", "SEES", "HEARS", "SMELLS", "NOHEAD", "HARDTOSHOOT", "SWIMS" ]
+    "flags": [ "ANIMAL", "SEES", "HEARS", "SMELLS", "NOHEAD", "HARDTOSHOOT" ]
   },
   {
     "id": "afs_mon_boatman",
@@ -206,7 +206,7 @@
     "harvest": "alien_small_fur",
     "path_settings": { "max_dist": 10 },
     "anger_triggers": [ "PLAYER_WEAK", "FRIEND_ATTACKED", "FRIEND_DIED" ],
-    "flags": [ "SEES", "SMELLS", "HEARS", "WARM", "SWIMS", "ANIMAL", "PATH_AVOID_DANGER", "STUMBLES" ]
+    "flags": [ "SEES", "SMELLS", "HEARS", "WARM", "ANIMAL", "PATH_AVOID_DANGER", "STUMBLES" ]
   },
   {
     "id": "afs_venandi",
diff --git a/data/mods/Aftershock/mobs/zombies.json b/data/mods/Aftershock/mobs/zombies.json
index dac408c223b38..63d1761c48a9f 100644
--- a/data/mods/Aftershock/mobs/zombies.json
+++ b/data/mods/Aftershock/mobs/zombies.json
@@ -168,7 +168,6 @@
       "SEES",
       "HEARS",
       "GOODHEARING",
-      "SWIMS",
       "WARM",
       "GROUP_BASH",
       "POISON",
@@ -214,7 +213,6 @@
       "SEES",
       "HEARS",
       "GOODHEARING",
-      "SWIMS",
       "WARM",
       "BASHES",
       "GROUP_BASH",
@@ -271,7 +269,6 @@
       "SEES",
       "HEARS",
       "GOODHEARING",
-      "SWIMS",
       "WARM",
       "GRABS",
       "BASHES",
@@ -321,7 +318,6 @@
       "SEES",
       "HEARS",
       "GOODHEARING",
-      "SWIMS",
       "WARM",
       "BASHES",
       "GROUP_BASH",
@@ -366,7 +362,6 @@
       "SEES",
       "HEARS",
       "GOODHEARING",
-      "SWIMS",
       "WARM",
       "GRABS",
       "BASHES",
@@ -411,7 +406,6 @@
       "SEES",
       "HEARS",
       "GOODHEARING",
-      "SWIMS",
       "WARM",
       "HAS_MIND",
       "BASHES",
@@ -469,7 +463,6 @@
       "HEARS",
       "GOODHEARING",
       "KEENNOSE",
-      "SWIMS",
       "WARM",
       "GRABS",
       "BASHES",
@@ -519,7 +512,6 @@
       "HEARS",
       "GOODHEARING",
       "KEENNOSE",
-      "SWIMS",
       "WARM",
       "BASHES",
       "GROUP_BASH",