diff --git a/src/timesfm/timesfm_2p5/timesfm_2p5_flax.py b/src/timesfm/timesfm_2p5/timesfm_2p5_flax.py
index aec4079..acd354b 100644
--- a/src/timesfm/timesfm_2p5/timesfm_2p5_flax.py
+++ b/src/timesfm/timesfm_2p5/timesfm_2p5_flax.py
@@ -509,7 +509,7 @@ class TimesFM_2p5_200M_flax(timesfm_2p5_base.TimesFM_2p5):
         self.model.o,
         new_horizon := math.ceil(fc.max_horizon / self.model.o) * self.model.o,
       )
-      forecast_config = dataclasses.replace(fc, max_horizon=new_horizon)
+      fc = dataclasses.replace(fc, max_horizon=new_horizon)
     if fc.max_context + fc.max_horizon > self.model.config.context_limit:
       raise ValueError(
         "Context + horizon must be less than the context limit."
diff --git a/src/timesfm/timesfm_2p5/timesfm_2p5_torch.py b/src/timesfm/timesfm_2p5/timesfm_2p5_torch.py
index fa57f14..c50be89 100644
--- a/src/timesfm/timesfm_2p5/timesfm_2p5_torch.py
+++ b/src/timesfm/timesfm_2p5/timesfm_2p5_torch.py
@@ -356,7 +356,7 @@ class TimesFM_2p5_200M_torch(timesfm_2p5_base.TimesFM_2p5, ModelHubMixin):
         self.model.o,
         new_horizon := math.ceil(fc.max_horizon / self.model.o) * self.model.o,
       )
-      forecast_config = dataclasses.replace(fc, max_horizon=new_horizon)
+      fc = dataclasses.replace(fc, max_horizon=new_horizon)
     if fc.max_context + fc.max_horizon > self.model.config.context_limit:
       raise ValueError(
         "Context + horizon must be less than the context limit."