diff --git a/imgaug/augmenters/blend.py b/imgaug/augmenters/blend.py
index <HASH>..<HASH> 100644
--- a/imgaug/augmenters/blend.py
+++ b/imgaug/augmenters/blend.py
@@ -387,6 +387,18 @@ class Alpha(meta.Augmenter):  # pylint: disable=locally-disabled, unused-variabl
             keypoints_on_images, random_state, parents, hooks, _augfunc
         )
 
+    def _augment_polygons(self, polygons_on_images, random_state, parents, hooks):
+        def _augfunc(augs_, polygons_on_images_, parents_, hooks_):
+            return augs_.augment_polygons(
+                keypoints_on_images=[polysoi_i.deepcopy() for polysoi_i in polygons_on_images_],
+                parents=parents_,
+                hooks=hooks_
+            )
+
+        return self._augment_coordinate_based(
+            polygons_on_images, random_state, parents, hooks, _augfunc
+        )
+
     def _augment_coordinate_based(self, inputs, random_state, parents, hooks, func):
         nb_images = len(inputs)
         if nb_images == 0:
Add polygon augmentation method to Alpha