diff --git a/element_deeplabcut/model.py b/element_deeplabcut/model.py
index 97379f6..8e83654 100644
--- a/element_deeplabcut/model.py
+++ b/element_deeplabcut/model.py
@@ -137,7 +137,7 @@ class RecordingInfo(dj.Imported):
     nframes                   : smallint  # number of frames 
     fps = NULL                : int     # (Hz) frames per second
     recording_datetime = NULL : datetime  # Datetime for the start of the recording
-    recording_duration = NULL : float     # video duration in seconds
+    recording_duration        : float     # video duration (s) from nframes / fps
     """
 
     @property
diff --git a/element_deeplabcut/train.py b/element_deeplabcut/train.py
index 6c20ce9..87b7e7c 100644
--- a/element_deeplabcut/train.py
+++ b/element_deeplabcut/train.py
@@ -106,6 +106,8 @@ class File(dj.Part):
         definition = """
         # Paths of training files (e.g., labeled pngs, CSV or video)
         -> master
+        file_id: int
+        ---
         file_path: varchar(255)
         """