diff --git a/comfy_extras/nodes_mask.py b/comfy_extras/nodes_mask.py
index aa13cac0..af7cb07b 100644
--- a/comfy_extras/nodes_mask.py
+++ b/comfy_extras/nodes_mask.py
@@ -327,15 +327,19 @@ class GrowMask:
         kernel = np.array([[c, 1, c],
                            [1, 1, 1],
                            [c, 1, c]])
-        output = mask.numpy().copy()
-        while expand < 0:
-            output = scipy.ndimage.grey_erosion(output, footprint=kernel)
-            expand += 1
-        while expand > 0:
-            output = scipy.ndimage.grey_dilation(output, footprint=kernel)
-            expand -= 1
-        output = torch.from_numpy(output)
-        return (output,)
+        mask = mask.reshape((-1, mask.shape[-2], mask.shape[-1]))
+        out = []
+        for m in mask:
+            output = m.numpy()
+            while expand < 0:
+                output = scipy.ndimage.grey_erosion(output, footprint=kernel)
+                expand += 1
+            while expand > 0:
+                output = scipy.ndimage.grey_dilation(output, footprint=kernel)
+                expand -= 1
+            output = torch.from_numpy(output)
+            out.append(output)
+        return (torch.cat(out, dim=0),)