diff --git a/pysr/sr.py b/pysr/sr.py
index 2c7d7653..d196ded8 100644
--- a/pysr/sr.py
+++ b/pysr/sr.py
@@ -1080,7 +1080,7 @@ def from_file(
             assert unary_operators is None
             assert n_features_in is None
             with open(pkl_filename, "rb") as f:
-                model: "pysr.sr.PySRRegressor" = pkl.load(f)
+                model = cast("PySRRegressor", pkl.load(f))
 
             # Update any parameters if necessary, such as
             # extra_sympy_mappings: