diff --git a/sphinx/domains/python.py b/sphinx/domains/python.py
index a749b8745..5c8780bfc 100644
--- a/sphinx/domains/python.py
+++ b/sphinx/domains/python.py
@@ -843,7 +843,10 @@ class PyAttribute(PyObject):
         typ = self.options.get('type')
         if typ:
             annotations = _parse_annotation(typ, self.env)
-            signode += addnodes.desc_annotation(typ, '', nodes.Text(': '), *annotations)
+            signode += addnodes.desc_annotation(typ, '',
+                                                addnodes.desc_sig_punctuation('', ':'),
+                                                addnodes.desc_sig_space(),
+                                                *annotations)
 
         value = self.options.get('value')
         if value:
diff --git a/tests/test_domain_py.py b/tests/test_domain_py.py
index 133427f82..f22f75c6c 100644
--- a/tests/test_domain_py.py
+++ b/tests/test_domain_py.py
@@ -835,15 +835,16 @@ def test_pyattribute(app):
     assert_node(doctree[1][1][0], addnodes.index,
                 entries=[('single', 'attr (Class attribute)', 'Class.attr', '', None)])
     assert_node(doctree[1][1][1], ([desc_signature, ([desc_name, "attr"],
-                                                     [desc_annotation, (": ",
+                                                     [desc_annotation, ([desc_sig_punctuation, ':'],
+                                                                        desc_sig_space,
                                                                         [pending_xref, "Optional"],
                                                                         [desc_sig_punctuation, "["],
                                                                         [pending_xref, "str"],
                                                                         [desc_sig_punctuation, "]"])],
                                                      [desc_annotation, " = ''"])],
                                    [desc_content, ()]))
-    assert_node(doctree[1][1][1][0][1][1], pending_xref, **{"py:class": "Class"})
-    assert_node(doctree[1][1][1][0][1][3], pending_xref, **{"py:class": "Class"})
+    assert_node(doctree[1][1][1][0][1][2], pending_xref, **{"py:class": "Class"})
+    assert_node(doctree[1][1][1][0][1][4], pending_xref, **{"py:class": "Class"})
     assert 'Class.attr' in domain.objects
     assert domain.objects['Class.attr'] == ('index', 'Class.attr', 'attribute', False)