diff --git a/finitewave/cpuwave2D/tracker/animation_2d_tracker.py b/finitewave/cpuwave2D/tracker/animation_2d_tracker.py
index ecc411e..988ecfd 100755
--- a/finitewave/cpuwave2D/tracker/animation_2d_tracker.py
+++ b/finitewave/cpuwave2D/tracker/animation_2d_tracker.py
@@ -39,7 +39,19 @@ def __init__(self):
         self.frame_type = "float64"   # Default frame format settings
         self._frame_counter = 0       # Internal frame counter
         self.overwrite = True         # Overwrite existing frames
-        self.file_name = "animation"  # Name of the animation file
+        self._file_name = None        # Name of the animation file
+
+    @property
+    def file_name(self):
+        if self._file_name is not None:
+            return self._file_name
+
+        path = Path(self.path, self.dir_name).parent
+        return path / "animation"
+
+    @file_name.setter
+    def file_name(self, file_name):
+        self._file_name = file_name
 
     def initialize(self, model):
         """
diff --git a/finitewave/tools/animation_2d_builder.py b/finitewave/tools/animation_2d_builder.py
index a68e27d..94eece6 100755
--- a/finitewave/tools/animation_2d_builder.py
+++ b/finitewave/tools/animation_2d_builder.py
@@ -41,7 +41,7 @@ def write(self, path, animation_name='animation', mask=None, shape_scale=1,
             Show progress bar.
         """
         path = Path(path)
-        path_save = path.parent.joinpath(animation_name).with_suffix(".mp4")
+        path_save = Path(animation_name).with_suffix(".mp4")
 
         files = natsorted(path.glob("*.npy"))