diff --git a/ultraplot/axes/plot.py b/ultraplot/axes/plot.py
index be24a8af4..9e7317397 100644
--- a/ultraplot/axes/plot.py
+++ b/ultraplot/axes/plot.py
@@ -4759,8 +4759,10 @@ def _parse_level_norm(
 
         Returns
         -------
-        norm : `~ultraplot.colors.DiscreteNorm`
-            The discrete normalizer.
+        norm : `~ultraplot.colors.DiscreteNorm` or `~matplotlib.colors.Normalize`
+            The discrete normalizer, or the original continuous normalizer when
+            ``min_levels=1`` (e.g. line contours) and the input norm is not a
+            `~matplotlib.colors.BoundaryNorm`.
         cmap : `~matplotlib.colors.Colormap`
             The possibly-modified colormap.
         kwargs