diff --git a/Lib/idlelib/FormatParagraph.py b/Lib/idlelib/FormatParagraph.py
index 9b10c0a..7a9d185 100644
--- a/Lib/idlelib/FormatParagraph.py
+++ b/Lib/idlelib/FormatParagraph.py
@@ -44,9 +44,11 @@
 
         The length limit parameter is for testing with a known value.
         """
-        if limit == None:
+        if limit is None:
+            # The default length limit is that defined by pep8
             limit = idleConf.GetOption(
-                    'main', 'FormatParagraph', 'paragraph', type='int')
+                'extensions', 'FormatParagraph', 'max-width',
+                type='int', default=72)
         text = self.editwin.text
         first, last = self.editwin.get_selection_indices()
         if first and last:
diff --git a/Lib/idlelib/config-extensions.def b/Lib/idlelib/config-extensions.def
index 5edbd98..a24b8c9 100644
--- a/Lib/idlelib/config-extensions.def
+++ b/Lib/idlelib/config-extensions.def
@@ -66,6 +66,7 @@
 
 [FormatParagraph]
 enable=True
+max-width=72
 [FormatParagraph_cfgBindings]
 format-paragraph=<Alt-Key-q>
 
diff --git a/Lib/idlelib/config-main.def b/Lib/idlelib/config-main.def
index 132797c..d7ad59f 100644
--- a/Lib/idlelib/config-main.def
+++ b/Lib/idlelib/config-main.def
@@ -58,9 +58,6 @@
 font-bold= 0
 encoding= none
 
-[FormatParagraph]
-paragraph=72
-
 [Indent]
 use-spaces= 1
 num-spaces= 4
diff --git a/Lib/idlelib/configDialog.py b/Lib/idlelib/configDialog.py
index 2187268..c416151 100644
--- a/Lib/idlelib/configDialog.py
+++ b/Lib/idlelib/configDialog.py
@@ -371,7 +371,6 @@
         parent = self.parent
         self.winWidth = StringVar(parent)
         self.winHeight = StringVar(parent)
-        self.paraWidth = StringVar(parent)
         self.startupEdit = IntVar(parent)
         self.autoSave = IntVar(parent)
         self.encoding = StringVar(parent)
@@ -387,7 +386,6 @@
         frameSave = LabelFrame(frame, borderwidth=2, relief=GROOVE,
                                text=' Autosave Preferences ')
         frameWinSize = Frame(frame, borderwidth=2, relief=GROOVE)
-        frameParaSize = Frame(frame, borderwidth=2, relief=GROOVE)
         frameEncoding = Frame(frame, borderwidth=2, relief=GROOVE)
         frameHelp = LabelFrame(frame, borderwidth=2, relief=GROOVE,
                                text=' Additional Help Sources ')
@@ -416,11 +414,6 @@
         labelWinHeightTitle = Label(frameWinSize, text='Height')
         entryWinHeight = Entry(
                 frameWinSize, textvariable=self.winHeight, width=3)
-        #paragraphFormatWidth
-        labelParaWidthTitle = Label(
-                frameParaSize, text='Paragraph reformat width (in characters)')
-        entryParaWidth = Entry(
-                frameParaSize, textvariable=self.paraWidth, width=3)
         #frameEncoding
         labelEncodingTitle = Label(
                 frameEncoding, text="Default Source Encoding")
@@ -458,7 +451,6 @@
         frameRun.pack(side=TOP, padx=5, pady=5, fill=X)
         frameSave.pack(side=TOP, padx=5, pady=5, fill=X)
         frameWinSize.pack(side=TOP, padx=5, pady=5, fill=X)
-        frameParaSize.pack(side=TOP, padx=5, pady=5, fill=X)
         frameEncoding.pack(side=TOP, padx=5, pady=5, fill=X)
         frameHelp.pack(side=TOP, padx=5, pady=5, expand=TRUE, fill=BOTH)
         #frameRun
@@ -475,9 +467,6 @@
         labelWinHeightTitle.pack(side=RIGHT, anchor=E, pady=5)
         entryWinWidth.pack(side=RIGHT, anchor=E, padx=10, pady=5)
         labelWinWidthTitle.pack(side=RIGHT, anchor=E, pady=5)
-        #paragraphFormatWidth
-        labelParaWidthTitle.pack(side=LEFT, anchor=W, padx=5, pady=5)
-        entryParaWidth.pack(side=RIGHT, anchor=E, padx=10, pady=5)
         #frameEncoding
         labelEncodingTitle.pack(side=LEFT, anchor=W, padx=5, pady=5)
         radioEncNone.pack(side=RIGHT, anchor=E, pady=5)
@@ -509,7 +498,6 @@
         self.keysAreBuiltin.trace_variable('w', self.VarChanged_keysAreBuiltin)
         self.winWidth.trace_variable('w', self.VarChanged_winWidth)
         self.winHeight.trace_variable('w', self.VarChanged_winHeight)
-        self.paraWidth.trace_variable('w', self.VarChanged_paraWidth)
         self.startupEdit.trace_variable('w', self.VarChanged_startupEdit)
         self.autoSave.trace_variable('w', self.VarChanged_autoSave)
         self.encoding.trace_variable('w', self.VarChanged_encoding)
@@ -594,10 +582,6 @@
         value = self.winHeight.get()
         self.AddChangedItem('main', 'EditorWindow', 'height', value)
 
-    def VarChanged_paraWidth(self, *params):
-        value = self.paraWidth.get()
-        self.AddChangedItem('main', 'FormatParagraph', 'paragraph', value)
-
     def VarChanged_startupEdit(self, *params):
         value = self.startupEdit.get()
         self.AddChangedItem('main', 'General', 'editor-on-startup', value)
@@ -1094,9 +1078,6 @@
                 'main', 'EditorWindow', 'width', type='int'))
         self.winHeight.set(idleConf.GetOption(
                 'main', 'EditorWindow', 'height', type='int'))
-        #initial paragraph reformat size
-        self.paraWidth.set(idleConf.GetOption(
-                'main', 'FormatParagraph', 'paragraph', type='int'))
         # default source encoding
         self.encoding.set(idleConf.GetOption(
                 'main', 'EditorWindow', 'encoding', default='none'))
diff --git a/Misc/NEWS b/Misc/NEWS
index af9274a..4754bd8 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -56,6 +56,11 @@
 IDLE
 ----
 
+- Issue #20577: Configuration of the max line length for the FormatParagraph
+  extension has been moved from the General tab of the Idle preferences dialog
+  to the FormatParagraph tab of the Config Extensions dialog.
+  Patch by Tal Einat.
+
 - Issue #16893: Update Idle doc chapter to match current Idle and add new
   information.