diff --git a/pydenticon/__init__.py b/pydenticon/__init__.py
index 147e63b48f417d4b81aad72eb75d8a183ba1a269..483e87609c932e55422172dd5379684f222b314c 100644
--- a/pydenticon/__init__.py
+++ b/pydenticon/__init__.py
@@ -226,8 +226,8 @@ class Generator(object):
                     # Set-up the coordinates for a block.
                     x1 = padding[2] + column * block_width
                     y1 = padding[0] + row * block_height
-                    x2 = padding[2] + (column + 1) * block_width
-                    y2 = padding[0] + (row + 1) * block_height
+                    x2 = padding[2] + (column + 1) * block_width - 1
+                    y2 = padding[0] + (row + 1) * block_height - 1
 
                     # Draw the rectangle.
                     draw.rectangle((x1, y1, x2, y2), fill=foreground)