diff --git a/tsmark/video_annotator.py b/tsmark/video_annotator.py
index c6cf04f..e260b79 100755
--- a/tsmark/video_annotator.py
+++ b/tsmark/video_annotator.py
@@ -861,10 +861,10 @@ class World:
                 w2 = max(1, a[3] / 2)
                 h2 = max(1, a[4] / 2)
                 return {
-                    "x0": int(a[1] - w2),
-                    "y0": int(a[2] - h2),
-                    "x1": int(a[1] + w2),
-                    "y1": int(a[2] + h2),
+                    "x0": max(0, int(a[1] - w2)),
+                    "y0": max(0, int(a[2] - h2)),
+                    "x1": min(self.video_res[0] - 1, int(a[1] + w2)),
+                    "y1": min(self.video_res[1] - 1, int(a[2] + h2)),
                     "type": "interp",
                     "visible": visible,
                 }