diff --git a/sphinx/domains/python/__init__.py b/sphinx/domains/python/__init__.py
index 674b59dc393..ca3eec07dbc 100644
--- a/sphinx/domains/python/__init__.py
+++ b/sphinx/domains/python/__init__.py
@@ -47,6 +47,7 @@
     PyGroupedField,
     PyTypedField,
     PyXrefMixin,
+    py_sig_re,
 )
 
 logger = logging.getLogger(__name__)