diff --git a/mercurial/configitems.py b/mercurial/configitems.py
--- a/mercurial/configitems.py
+++ b/mercurial/configitems.py
@@ -338,6 +338,9 @@ coreconfigitem('profiling', 'nested',
 coreconfigitem('profiling', 'output',
     default=None,
 )
+coreconfigitem('profiling', 'showmax',
+    default=0.999,
+)
 coreconfigitem('profiling', 'sort',
     default='inlinetime',
 )
diff --git a/mercurial/profiling.py b/mercurial/profiling.py
--- a/mercurial/profiling.py
+++ b/mercurial/profiling.py
@@ -138,7 +138,7 @@ def statprofile(ui, fp):
 
         if profformat == 'chrome':
             showmin = ui.configwith(fraction, 'profiling', 'showmin', 0.005)
-            showmax = ui.configwith(fraction, 'profiling', 'showmax', 0.999)
+            showmax = ui.configwith(fraction, 'profiling', 'showmax')
             kwargs.update(minthreshold=showmin, maxthreshold=showmax)
         elif profformat == 'hotpath':
             # inconsistent config: profiling.showmin