diff --git a/CHANGES b/CHANGES
index 11e9f9306..e52ff3ab0 100644
--- a/CHANGES
+++ b/CHANGES
@@ -110,6 +110,7 @@ Features added
 * #1210: ``eqref`` role now supports cross reference
 * #2892: Added ``-a`` (``--append-syspath``) option to ``sphinx-apidoc``
 * #1604: epub3 builder: Obey font-related CSS when viewing in iBooks.
+* #646: ``option`` directive support '.' character as a part of options
 
 Bugs fixed
 ----------
diff --git a/sphinx/domains/std.py b/sphinx/domains/std.py
index ca82bcdd2..95ed17c42 100644
--- a/sphinx/domains/std.py
+++ b/sphinx/domains/std.py
@@ -28,7 +28,7 @@ from sphinx.util.compat import Directive
 
 
 # RE for option descriptions
-option_desc_re = re.compile(r'((?:/|--|-|\+)?[-?@#_a-zA-Z0-9]+)(=?\s*.*)')
+option_desc_re = re.compile(r'((?:/|--|-|\+)?[-\.?@#_a-zA-Z0-9]+)(=?\s*.*)')
 # RE for grammar tokens
 token_re = re.compile('`(\w+)`', re.U)
 
diff --git a/tests/root/objects.txt b/tests/root/objects.txt
index 3756677e9..1fc23567a 100644
--- a/tests/root/objects.txt
+++ b/tests/root/objects.txt
@@ -172,9 +172,13 @@ Others
 
 .. option:: +p
 
+.. option:: --plugin.option
+
+.. option:: create-auth-token
+
 .. option:: arg
 
-Link to :option:`perl +p` and :option:`arg`
+Link to :option:`perl +p`, :option:`--plugin.option`, :option:`create-auth-token` and :option:`arg`
 
 .. program:: hg
 
diff --git a/tests/test_build_html.py b/tests/test_build_html.py
index 6d050037d..658ffdf60 100644
--- a/tests/test_build_html.py
+++ b/tests/test_build_html.py
@@ -244,6 +244,10 @@ HTML_XPATH = {
             'perl'),
         (".//a[@class='reference internal'][@href='#cmdoption-perl-arg-+p']/code/span",
             '\+p'),
+        (".//a[@class='reference internal'][@href='#cmdoption-perl--plugin.option']/code/span",
+            '--plugin.option'),
+        (".//a[@class='reference internal'][@href='#cmdoption-perl-arg-create-auth-token']/code/span",
+            'create-auth-token'),
         (".//a[@class='reference internal'][@href='#cmdoption-perl-arg-arg']/code/span",
             'arg'),
         (".//a[@class='reference internal'][@href='#cmdoption-hg-arg-commit']/code/span",