diff --git a/pts/feature/time_feature.py b/pts/feature/time_feature.py
index f3b7793..cc9cec9 100644
--- a/pts/feature/time_feature.py
+++ b/pts/feature/time_feature.py
@@ -112,9 +112,9 @@ class WeekOfYear(TimeFeature):
 
     def __call__(self, index: pd.DatetimeIndex) -> np.ndarray:
         if self.normalized:
-            return index.weekofyear / 51.0 - 0.5
+            return pd.Int64Index(index.isocalendar().week) / 51.0 - 0.5
         else:
-            return index.weekofyear.map(float)
+            return pd.Int64Index(index.isocalendar().week).map(float)
 
 
 class FourierDateFeatures(TimeFeature):
diff --git a/setup.py b/setup.py
index d1efe16..7435167 100644
--- a/setup.py
+++ b/setup.py
@@ -19,7 +19,7 @@ setup(
         'torch>=1.5.0',
         'holidays',
         'numpy',
-        'pandas>=1.0,<1.1',
+        'pandas>=1.1',
         'scipy',
         'tqdm',
         'pydantic',