diff --git a/README.md b/README.md
index 44b23c8..9be8862 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,7 @@ Map Italy - Along Track Grid
     >     ([Link][2]);
 
 
-
+----
 #### PYTHON DEPENDENCIES:
 - [gdal: Python's GDAL binding.][]
 - [fiona: Fiona is GDAL’s neat and nimble vector API for Python programmers.][]
diff --git a/rm_z_coord.py b/rm_z_coord.py
index 9b00528..35d93d1 100644
--- a/rm_z_coord.py
+++ b/rm_z_coord.py
@@ -6,7 +6,8 @@
 January 2024
 
 Remove z coordinate from a GeoDataFrame.
-Convert a GeoDataFrame with z coordinate to a GeoDataFrame without z coordinate.
+Convert a GeoDataFrame with z coordinate to a GeoDataFrame
+without z coordinate.
 """
 
 
diff --git a/test/test_generate_grid.py b/test/test_generate_grid.py
index 766b182..b68c1a3 100644
--- a/test/test_generate_grid.py
+++ b/test/test_generate_grid.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python
+""" Unit tests for the generate_grid function. """
 import geopandas as gpd
 from shapely.geometry import Polygon
 from generate_grid import generate_grid
diff --git a/test/test_rm_z_coords.py b/test/test_rm_z_coords.py
new file mode 100644
index 0000000..02e9092
--- /dev/null
+++ b/test/test_rm_z_coords.py
@@ -0,0 +1,19 @@
+#!/usr/bin/env python
+""" Unit tests for the rm_z_coord function. """
+import geopandas as gpd
+from shapely.geometry import Polygon
+from rm_z_coord import rm_z_coord
+
+
+def test_rm_z_coord():
+    # Create a GeoDataFrame for testing
+    data = {'geometry': [Polygon([(0, 0, 1), (1, 0, 2),
+                                  (1, 1, 3), (0, 1, 4)])]}
+    gdf = gpd.GeoDataFrame(data, crs='EPSG:4326')
+
+    # Apply the function
+    result_gdf = rm_z_coord(gdf.copy())
+
+    # Check if the z-coordinate is removed from the geometry
+    assert all(result_gdf['geometry'].apply(lambda geom:
+                                            len(geom.exterior.coords[0]) == 2))