diff --git a/doc/help/commands.asciidoc b/doc/help/commands.asciidoc
index 4ce944652..0e519e2a8 100644
--- a/doc/help/commands.asciidoc
+++ b/doc/help/commands.asciidoc
@@ -128,7 +128,7 @@ possible to run or bind multiple commands by separating them with `;;`.
 |<<tab-prev,tab-prev>>|Switch to the previous tab, or switch [count] tabs back.
 |<<tab-take,tab-take>>|Take a tab from another window.
 |<<unbind,unbind>>|Unbind a keychain.
-|<<undo,undo>>|Re-open the last closed tab or tabs.
+|<<undo,undo>>|Re-open the last closed tab(s) or window.
 |<<version,version>>|Show version information.
 |<<view-source,view-source>>|Show the source of the current page in a new tab.
 |<<window-only,window-only>>|Close all windows except for the current one.
@@ -1467,7 +1467,12 @@ Unbind a keychain.
 
 [[undo]]
 === undo
-Re-open the last closed tab or tabs.
+Syntax: +:undo [*--window*]+
+
+Re-open the last closed tab(s) or window.
+
+==== optional arguments
+* +*-w*+, +*--window*+: Re-open the last closed window (and its tabs).
 
 [[version]]
 === version
diff --git a/doc/help/settings.asciidoc b/doc/help/settings.asciidoc
index e4eb8bc54..0ec9f1e1a 100644
--- a/doc/help/settings.asciidoc
+++ b/doc/help/settings.asciidoc
@@ -606,6 +606,7 @@ Default:
 * +pass:[Sq]+: +pass:[open qute://bookmarks]+
 * +pass:[Ss]+: +pass:[open qute://settings]+
 * +pass:[T]+: +pass:[tab-focus]+
+* +pass:[U]+: +pass:[undo -w]+
 * +pass:[V]+: +pass:[enter-mode caret ;; toggle-selection --line]+
 * +pass:[ZQ]+: +pass:[quit]+
 * +pass:[ZZ]+: +pass:[quit --save]+
diff --git a/qutebrowser/app.py b/qutebrowser/app.py
index a1e633ff5..d9fcbfa0d 100644
--- a/qutebrowser/app.py
+++ b/qutebrowser/app.py
@@ -533,8 +533,11 @@ class Application(QApplication):
             tab_stack=window.tabbed_browser._undo_stack,
         ))
 
-    @cmdutils.register(instance='app')
     def undo_last_window_close(self):
+        """Restore the last window to be closed.
+
+        It will have the same tab and undo stack as when it was closed.
+        """
         event = self._undos.pop()
         window = mainwindow.MainWindow(
             private=event.private,
diff --git a/qutebrowser/browser/commands.py b/qutebrowser/browser/commands.py
index e2cef8003..1b39ea062 100644
--- a/qutebrowser/browser/commands.py
+++ b/qutebrowser/browser/commands.py
@@ -780,10 +780,18 @@ class CommandDispatcher:
                 text="Are you sure you want to close pinned tabs?")
 
     @cmdutils.register(instance='command-dispatcher', scope='window')
-    def undo(self):
-        """Re-open the last closed tab or tabs."""
+    def undo(self, window: bool = False):
+        """Re-open the last closed tab(s) or window.
+
+        Args:
+            window: Re-open the last closed window (and its tabs).
+        """
         try:
-            self._tabbed_browser.undo()
+            if window:
+                app = QApplication.instance()
+                app.undo_last_window_close()
+            else:
+                self._tabbed_browser.undo()
         except IndexError:
             raise cmdutils.CommandError("Nothing to undo!")
 
diff --git a/qutebrowser/config/configdata.yml b/qutebrowser/config/configdata.yml
index 8b3d2a373..e5e762ca5 100644
--- a/qutebrowser/config/configdata.yml
+++ b/qutebrowser/config/configdata.yml
@@ -3099,6 +3099,7 @@ bindings.default:
       k: scroll up
       l: scroll right
       u: undo
+      U: undo -w
       <Ctrl-Shift-T>: undo
       gg: scroll-to-perc 0
       G: scroll-to-perc