diff --git a/pedpy/methods/flow_calculator.py b/pedpy/methods/flow_calculator.py
index d0b8a1cf..48b372b2 100644
--- a/pedpy/methods/flow_calculator.py
+++ b/pedpy/methods/flow_calculator.py
@@ -73,7 +73,7 @@ def compute_n_t(
                 )
             )
         )
-        .fillna(method="ffill")
+        .ffill()
         .fillna(0)
     )
 
diff --git a/pedpy/methods/method_utils.py b/pedpy/methods/method_utils.py
index 25a4b8e9..8d914ad8 100644
--- a/pedpy/methods/method_utils.py
+++ b/pedpy/methods/method_utils.py
@@ -805,7 +805,7 @@ def _compute_movememnt_adaptive_border(
     df_movement = traj_data.data.copy(deep=True)
 
     frame_infos = df_movement.groupby(by=ID_COL).agg(
-        frame_min=(FRAME_COL, np.min), frame_max=(FRAME_COL, np.max)
+        frame_min=(FRAME_COL, min), frame_max=(FRAME_COL, max)
     )
     df_movement = df_movement.merge(frame_infos, on=ID_COL)