diff --git a/news/258.bugfix.md b/news/258.bugfix.md
new file mode 100644
index 00000000..c59e0b79
--- /dev/null
+++ b/news/258.bugfix.md
@@ -0,0 +1 @@
+Fix built-in help command requiring quotes for nested subcommands
diff --git a/src/cleo/commands/help_command.py b/src/cleo/commands/help_command.py
index a52713eb..c949f4b5 100644
--- a/src/cleo/commands/help_command.py
+++ b/src/cleo/commands/help_command.py
@@ -16,7 +16,8 @@ class HelpCommand(Command):
             "command_name",
             required=False,
             description="The command name",
-            default="help",
+            default=["help"],
+            is_list=True,
         )
     ]
 
@@ -43,7 +44,12 @@ def handle(self) -> int:
 
         if self._command is None:
             assert self._application is not None
-            self._command = self._application.find(self.argument("command_name"))
+            command_name = self.argument("command_name")
+            if isinstance(command_name, list):
+                command_name = " ".join(command_name)
+            if not command_name:
+                command_name = "help"
+            self._command = self._application.find(command_name)
 
         self.line("")
         TextDescriptor().describe(self._io, self._command)
diff --git a/tests/fixtures/application_run5.txt b/tests/fixtures/application_run5.txt
index a322d59f..22244549 100644
--- a/tests/fixtures/application_run5.txt
+++ b/tests/fixtures/application_run5.txt
@@ -3,10 +3,10 @@ Description:
   Displays help for a command.
 
 Usage:
-  help [options] [--] [<command_name>]
+  help [options] [--] [<command_name>...]
 
 Arguments:
-  command_name          The command name [default: "help"]
+  command_name          The command name [default: ["help"]]
 
 Options:
   -h, --help            Display help for the given command. When no command is given display help for the list command.
diff --git a/tests/test_application.py b/tests/test_application.py
index f08286a4..ca4b4fe6 100644
--- a/tests/test_application.py
+++ b/tests/test_application.py
@@ -346,6 +346,30 @@ def test_run_with_help(tester: ApplicationTester) -> None:
     ).read_text(encoding="utf-8")
 
 
+def test_run_help_with_nested_subcommand() -> None:
+    app = Application()
+    app.add(FooSubNamespaced1Command())
+
+    tester1 = ApplicationTester(app)
+    exit1 = tester1.execute("help foo bar baz")
+    output1 = tester1.io.fetch_output()
+
+    tester2 = ApplicationTester(app)
+    exit2 = tester2.execute('help "foo bar baz"')
+    output2 = tester2.io.fetch_output()
+
+    tester3 = ApplicationTester(app)
+    exit3 = tester3.execute("--help foo bar baz")
+    output3 = tester3.io.fetch_output()
+
+    assert exit1 == 0
+    assert exit2 == 0
+    assert exit3 == 0
+    assert "The foo bar baz command" in output1
+    assert output1 == output2
+    assert output1 == output3
+
+
 def test_run_with_input() -> None:
     app = Application()
     command = Foo3Command()