diff --git a/mapclassify/tests/test_rgba.py b/mapclassify/tests/test_rgba.py
index 02f4bee..44729ec 100644
--- a/mapclassify/tests/test_rgba.py
+++ b/mapclassify/tests/test_rgba.py
@@ -5,7 +5,7 @@
 
 world = geopandas.read_file(
     "https://naciscdn.org/naturalearth/110m/cultural/ne_110m_admin_0_countries.zip"
-)
+).reset_index(drop=True)
 
 
 def test_rgba():
@@ -13,7 +13,21 @@ def test_rgba():
     assert_array_equal(colors, np.array([68, 1, 84, 255])) 
     
 
-def test_rgba():
+def test_rgba_hex():
     colors = get_color_array(world.area, cmap="viridis", as_hex=True)[0]
     assert_array_equal(colors,'#440154') 
     
+def test_rgba_nan():
+    worldnan = world.copy()
+    worldnan['area'] = worldnan.area
+    worldnan.loc[0, 'area'] = np.nan
+    colors = get_color_array(worldnan['area'], cmap="viridis", nan_color=[0,0,0,0])[0]
+    assert_array_equal(colors, np.array([0, 0, 0, 0])) 
+
+def test_rgba_nan_hex():
+    worldnan = world.copy()
+    worldnan['area'] = worldnan.area
+    worldnan.loc[0, 'area'] = np.nan
+    colors = get_color_array(worldnan['area'], cmap="viridis",nan_color=[0,0,0,0], as_hex=True)[0]
+    assert_array_equal(colors, np.array(['#000000'])) 
+    
\ No newline at end of file