diff --git a/wisp/ops/image/metrics.py b/wisp/ops/image/metrics.py
index 2c8eb69..f18f3fe 100644
--- a/wisp/ops/image/metrics.py
+++ b/wisp/ops/image/metrics.py
@@ -84,7 +84,6 @@ def ssim(rgb, gts):
     return skimage.metrics.structural_similarity(
         rgb[..., :3].cpu().numpy(),
         gts[..., :3].cpu().numpy(),
-        channel_axis=2,
         data_range=1,
         gaussian_weights=True,
         sigma=1.5,