diff --git a/tsai/data/preprocessing.py b/tsai/data/preprocessing.py
index 59dce9ab..49fa7649 100644
--- a/tsai/data/preprocessing.py
+++ b/tsai/data/preprocessing.py
@@ -292,7 +292,12 @@ def encodes(self, o:TSTensor):
             else:
                 _min, _max = o.mul_min(self.axes, keepdim=self.axes!=()), o.mul_max(self.axes, keepdim=self.axes!=())
             self.min, self.max = _min, _max
-        output = ((o - self.min) / (self.max - self.min)) * (self.range_max - self.range_min) + self.range_min
+        diff = (self.max - self.min)
+        output = torch.where(
+            diff != 0,
+            ((o - self.min) / diff) * (self.range_max - self.range_min) + self.range_min,
+            torch.tensor(self.range_min, dtype=o.dtype, device=o.device),
+        )
         if self.clip_values:
             if self.by_var and is_listy(self.by_var):
                 for v in self.by_var: