diff --git a/masque/shapes/path.py b/masque/shapes/path.py
index 675029a..3ce8f8c 100644
--- a/masque/shapes/path.py
+++ b/masque/shapes/path.py
@@ -144,7 +144,8 @@ class Path(Shape):
                  vertices: numpy.ndarray,
                  width: float = 0.0,
                  cap: 'Path.Cap' = Cap.Flush,
-                 offset: vector2=(0.0, 0.0),
+                 cap_extensions: numpy.ndarray = None,
+                 offset: vector2 = (0.0, 0.0),
                  rotation: float = 0,
                  mirrored: Tuple[bool] = (False, False),
                  layer: int=0,