diff --git a/lang/string_extractor/parsers/overmap_special.py b/lang/string_extractor/parsers/overmap_special.py
index 57e3cc6eb5c53..e1be1f2b0808e 100644
--- a/lang/string_extractor/parsers/overmap_special.py
+++ b/lang/string_extractor/parsers/overmap_special.py
@@ -1,8 +1,14 @@
 from ..write_text import write_text
 
+def parse_camp_name(overmap, origin):
+    if "camp_name" in overmap:
+        write_text(overmap["camp_name"], origin,
+            comment="Name of NPC faction camp")
 
 def parse_overmap_special(json, origin):
-    for overmap in json["overmaps"]:
-        if "camp_name" in overmap:
-            write_text(overmap["camp_name"], origin,
-                       comment="Name of NPC faction camp")
+    if "subtype" in json and json["subtype"] == "mutable":
+        for mutable_overmap, overmap in json["overmaps"]:
+            parse_camp_name(overmap, origin)
+    else:
+        for overmap in json["overmaps"]:
+            parse_camp_name(overmap, origin)