diff --git a/src/robofish/io/file.py b/src/robofish/io/file.py
index 94ce119bdbf39869708435d4fb723a01df271f20..434b3d3fd6bc81b8e17b581e9d70c56dbd490d88 100644
--- a/src/robofish/io/file.py
+++ b/src/robofish/io/file.py
@@ -1471,6 +1471,8 @@ class File(h5py.File):
             )
 
         if video_path is not None:
+            if not video_path.suffix:
+                video_path = video_path.parent / f"{video_path.stem}.mp4"
             if video_path.exists():
                 if input(f"Video {str(video_path)} exists. Overwrite? (y/n)") == "y":
                     video_path.unlink()