diff --git a/python_scripts/add_trees_to_open_street_map/add_trees.py b/python_scripts/add_trees_to_open_street_map/add_trees.py
index 48c35a6c41106b6f79e0d846fa528e5d42ed2386..32e10df96cac977d7a875e977bc95039b68a289f 100644
--- a/python_scripts/add_trees_to_open_street_map/add_trees.py
+++ b/python_scripts/add_trees_to_open_street_map/add_trees.py
@@ -51,7 +51,7 @@ OUTPUT_DIR = SCRIPT_DIR / 'output'
 Bounds = namedtuple("Bounds", "W S E N")
 
 
-def load_region(wkt_polygon):
+def load_region(wkt_polygon: str):
     region = wkt.loads(wkt_polygon)
     bounds = Bounds(*region.bounds)
     return region, bounds
@@ -61,7 +61,7 @@ def get_basename(bounds):
     return f'{bounds.S}__{bounds.N}__{bounds.W}__{bounds.E}_{TREE_DISTANCE}m'.replace('.', '_')
 
 
-def get_osm_roads(bounds):
+def get_osm_roads(bounds: Bounds):
     cache_dir = SCRIPT_DIR / 'cache'
     cache_dir.mkdir(exist_ok=True)
 
@@ -103,7 +103,7 @@ def set_plot(bounds, to_local_coordinates):
     return ax
 
 
-def place_trees(forest, ways, region, to_local, tree_distance, min_distance_2) -> Forest:
+def place_trees(forest: Forest, ways: list, region: str, to_local, tree_distance: float, min_distance_2: float) -> Forest:
     local_region = transform(to_local.transform, region)
 
     for way in ways:
@@ -164,7 +164,7 @@ def plot_trees(bounds: Bounds, forest: Forest, tree_distance: float) -> None:
     print("  DONE!")
 
 
-def export_map(bounds, forest, epsg_id) -> None:
+def export_map(bounds: Bounds, forest: Forest, epsg_id: str) -> None:
     print("Exporting Map...")
     to_wgs84 = Transformer.from_crs(f"EPSG:{epsg_id}", "EPSG:4326", always_xy=True)
     interactive_map = folium.Map()
@@ -197,7 +197,7 @@ def export_map(bounds, forest, epsg_id) -> None:
     print("  DONE!")
 
 
-def export_csv(bounds, forest, wkt_polygon, tree_distance, min_distance, epsg_id) -> None:
+def export_csv(bounds: Bounds, forest: Forest, wkt_polygon: str, tree_distance: float, min_distance: float, epsg_id: str) -> None:
     print("Exporting CSV...")
     with open(OUTPUT_DIR / f"{get_basename(bounds)}_trees.csv", "w") as csv:
         csv.write(f"# Fake trees for; {wkt_polygon}\n")
@@ -239,7 +239,7 @@ def export_shapefile(bounds: Bounds, forest: Forest, epsg_id: str) -> None:
     print("  DONE!")
 
 
-def main(wkt_polygon, epsg_id, tree_distance, min_distance, import_tree_shp) -> None:
+def main(wkt_polygon: str, epsg_id: str, tree_distance: float, min_distance: float, import_tree_shp) -> None:
     region, bounds = load_region(wkt_polygon)
     ways = get_osm_roads(bounds)