diff --git a/pyproject.toml b/pyproject.toml
index 062098d..9a29065 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -56,6 +56,7 @@ dxf = ["ezdxf~=1.0.2"]
 svg = ["svgwrite"]
 visualize = ["matplotlib"]
 text = ["matplotlib", "freetype-py"]
+manhatanize_slow = ["float_raster"]
 
 
 [tool.ruff]