diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -1985,7 +1985,7 @@ def help_(ui, name=None, with_version=Fa
     Returns 0 if successful.
     """
     option_lists = []
-    textwidth = ui.termwidth() - 2
+    textwidth = min(ui.termwidth(), 80) - 2
 
     def addglobalopts(aliases):
         if ui.verbose: