diff --git a/resources/tools/generate_landmap.py b/resources/tools/generate_landmap.py
index 60f17ad4..6fb52796 100644
--- a/resources/tools/generate_landmap.py
+++ b/resources/tools/generate_landmap.py
@@ -32,40 +32,53 @@ def _geometry_collection_to_multipoly(obj: GeometryCollection) -> MultiPolygon:
     raise RuntimeError(f"Not sure how to convert collection to multipoly: {obj.wkt}")
 
 
-for terrain in ["cau", "nev", "syria", "channel", "normandy", "gulf", "marianaislands"]:
-    print("Terrain " + terrain)
-    m = Mission()
-    m.load_file("./{}_terrain.miz".format(terrain))
+def main() -> None:
+    for terrain in [
+        "cau",
+        "nev",
+        "syria",
+        "channel",
+        "normandy",
+        "gulf",
+        "marianaislands",
+    ]:
+        print("Terrain " + terrain)
+        m = Mission()
+        m.load_file("./{}_terrain.miz".format(terrain))
 
-    inclusion_zones = []
-    exclusion_zones = []
-    seas_zones = []
-    for plane_group in m.country("USA").plane_group:
-        zone = [(x.position.x, x.position.y) for x in plane_group.points]
+        inclusion_zones = []
+        exclusion_zones = []
+        seas_zones = []
+        for plane_group in m.country("USA").plane_group:
+            zone = [(x.position.x, x.position.y) for x in plane_group.points]
 
-        if terrain == "cau" and inclusion_zones:
-            # legacy
-            exclusion_zones.append(Polygon(zone))
-        else:
-            poly = Polygon(zone)
-            if not poly.is_valid:
-                raise RuntimeError(f"{plane_group} is invalid")
-            if plane_group.units[0].type == "F-15C":
-                exclusion_zones.append(poly)
+            if terrain == "cau" and inclusion_zones:
+                # legacy
+                exclusion_zones.append(Polygon(zone))
             else:
-                inclusion_zones.append(poly)
+                poly = Polygon(zone)
+                if not poly.is_valid:
+                    raise RuntimeError(f"{plane_group} is invalid")
+                if plane_group.units[0].type == "F-15C":
+                    exclusion_zones.append(poly)
+                else:
+                    inclusion_zones.append(poly)
 
-    for ship_group in m.country("USA").ship_group:
-        zone = [(x.position.x, x.position.y) for x in ship_group.points]
-        seas_zones.append(Polygon(zone))
+        for ship_group in m.country("USA").ship_group:
+            zone = [(x.position.x, x.position.y) for x in ship_group.points]
+            seas_zones.append(Polygon(zone))
 
-    with open("../{}landmap.p".format(terrain), "wb") as f:
-        print(len(inclusion_zones), len(exclusion_zones), len(seas_zones))
-        pickle.dump(
-            Landmap(
-                to_multipoly(unary_union(inclusion_zones)),
-                to_multipoly(unary_union(exclusion_zones)),
-                to_multipoly(unary_union(seas_zones)),
-            ),
-            f,
-        )
+        with open("../{}landmap.p".format(terrain), "wb") as f:
+            print(len(inclusion_zones), len(exclusion_zones), len(seas_zones))
+            pickle.dump(
+                Landmap(
+                    to_multipoly(unary_union(inclusion_zones)),
+                    to_multipoly(unary_union(exclusion_zones)),
+                    to_multipoly(unary_union(seas_zones)),
+                ),
+                f,
+            )
+
+
+if __name__ == "__main__":
+    main()