diff --git a/wall_x/model/core/action/normalizer.py b/wall_x/model/core/action/normalizer.py
index 5c1a7d8..20af594 100644
--- a/wall_x/model/core/action/normalizer.py
+++ b/wall_x/model/core/action/normalizer.py
@@ -285,9 +285,9 @@ class Normalizer(nn.Module):
         new_xs = []
         dataset_names = [name for name in dataset_names if name != "x2_multimodal"]
         for x, dataset_name in zip(xs, dataset_names):
-            # if dataset_name == "ex_normal":
-            # dataset_name = "x2_normal"
-            x = (x - self.min[dataset_name]) / (self.delta[dataset_name])
+            delta = self.delta[dataset_name]
+            delta = torch.where(delta == 0, torch.ones_like(delta), delta)
+            x = (x - self.min[dataset_name]) / delta
             x = x * 2 - 1
             x = torch.clamp(x, -1, 1)
             new_xs.append(x)