diff --git a/lib/matplotlib/_mathtext.py b/lib/matplotlib/_mathtext.py
index cf2717119b7e..79f8e1a1d3b5 100644
--- a/lib/matplotlib/_mathtext.py
+++ b/lib/matplotlib/_mathtext.py
@@ -1680,7 +1680,7 @@ class _MathStyle(enum.Enum):
 
     _ambi_delim = set(r"""
       | \| / \backslash \uparrow \downarrow \updownarrow \Uparrow
-      \Downarrow \Updownarrow . \vert \Vert \\|""".split())
+      \Downarrow \Updownarrow . \vert \Vert""".split())
 
     _left_delim = set(r"( [ \{ < \lfloor \langle \lceil".split())