diff --git a/lib/matplotlib/offsetbox.py b/lib/matplotlib/offsetbox.py
index a3693c9cd219..15c4e0928ba3 100644
--- a/lib/matplotlib/offsetbox.py
+++ b/lib/matplotlib/offsetbox.py
@@ -1428,7 +1428,7 @@ def __init__(self, offsetbox, xy,
                  xybox=None,
                  xycoords='data',
                  boxcoords=None,
-                 frameon=True, pad=0.4,  # BboxPatch
+                 frameon=True, pad=0.4,  # FancyBboxPatch boxstyle.
                  annotation_clip=None,
                  box_alignment=(0.5, 0.5),
                  bboxprops=None,