diff --git a/doc/usage/restructuredtext/domains.rst b/doc/usage/restructuredtext/domains.rst
index f2f07927d..cc0713b9f 100644
--- a/doc/usage/restructuredtext/domains.rst
+++ b/doc/usage/restructuredtext/domains.rst
@@ -1803,7 +1803,8 @@ There is a set of directives allowing documenting command-line programs:
.. versionchanged:: 5.3
- One can cross-reference including an option value: ``:option:`--module=foobar```.
+ One can cross-reference including an option value: ``:option:`--module=foobar```,
+ ,``:option:`--module[=foobar]``` or ``:option:`--module foobar```.
Use :confval:`option_emphasise_placeholders` for parsing of
"variable part" of a literal text (similarly to the :rst:role:`samp` role).
diff --git a/sphinx/domains/std.py b/sphinx/domains/std.py
index ef13e156e..6154a6ac1 100644
--- a/sphinx/domains/std.py
+++ b/sphinx/domains/std.py
@@ -943,10 +943,17 @@ class StandardDomain(Domain):
progname = node.get('std:program')
target = target.strip()
docname, labelid = self.progoptions.get((progname, target), ('', ''))
- # for :option:`-foo=bar` search for -foo option directive
- if not docname and '=' in target:
- target2 = target[:target.find('=')]
- docname, labelid = self.progoptions.get((progname, target2), ('', ''))
+ if not docname:
+ # Support also reference that contain an option value:
+ # * :option:`-foo=bar`
+ # * :option:`-foo[=bar]`
+ # * :option:`-foo bar`
+ for needle in {'=', '[=', ' '}:
+ if needle in target:
+ stem, _, _ = target.partition(needle)
+ docname, labelid = self.progoptions.get((progname, stem), ('', ''))
+ if docname:
+ break
if not docname:
commands = []
while ws_re.search(target):
diff --git a/tests/roots/test-root/objects.txt b/tests/roots/test-root/objects.txt
index fa9e475e5..170c026e7 100644
--- a/tests/roots/test-root/objects.txt
+++ b/tests/roots/test-root/objects.txt
@@ -214,7 +214,8 @@ Test repeated option directive.
My secret API.
-Reference the first option :option:`-mapi=secret`.
+Reference the first option :option:`-mapi=secret`, :option:`-mapi[=xxx]`
+or :option:`-mapi with_space`.
User markup
diff --git a/tests/test_build_html.py b/tests/test_build_html.py
index 453225e18..138f8a9c1 100644
--- a/tests/test_build_html.py
+++ b/tests/test_build_html.py
@@ -1771,6 +1771,9 @@ def test_option_reference_with_value(app, status, warning):
assert ('-mapi'
''
+ '-mapi[=xxx]
') in content
+ assert '-mapi with_space' in content
@pytest.mark.sphinx('html', testroot='theming')