diff --git a/tsmark/video_annotator.py b/tsmark/video_annotator.py
index b3ff7de..fa1eaea 100755
--- a/tsmark/video_annotator.py
+++ b/tsmark/video_annotator.py
@@ -707,7 +707,7 @@ class World:
                     age = 0
                 if self.points_interpolated[point_index][key]["type"] == "interp":
                     age += 1
-                    self.points_interpolated[point_index][key]["type"] = age
+                self.points_interpolated[point_index][key]["age"] = age
 
     def draw_help(self, frame):