diff --git a/geotile/__version__.py b/geotile/__version__.py
index 4614d7d..f12aba5 100644
--- a/geotile/__version__.py
+++ b/geotile/__version__.py
@@ -6,4 +6,4 @@
 
 __author__ = "Tek Kshetri"
 __email__ = "iamtekson@gmail.com"
-__version__ = "0.3.0"
+__version__ = "0.3.1"
diff --git a/geotile/utils.py b/geotile/utils.py
index 9f3c6fd..ea3b590 100644
--- a/geotile/utils.py
+++ b/geotile/utils.py
@@ -64,7 +64,7 @@ def mosaic(input_folder: str, output_file: str, image_format: Optional[str] = 't
 
 
 # vectorize the tiles
-def vectorize(input_raster: str, output_file:str, band (Optional: str) = 1, mask (Optional: str) = None):
+def vectorize(input_raster: str, output_file:str, band: Optional[int] = 1, mask: Optional[str] = None):
     """Vectorize the raster
 
         This method is used to vectorize the raster