diff --git a/numpydoc/numpydoc.py b/numpydoc/numpydoc.py
index d59c5f0b..2fcf1894 100644
--- a/numpydoc/numpydoc.py
+++ b/numpydoc/numpydoc.py
@@ -114,8 +114,9 @@ def mangle_signature(app, what, name, obj, options, sig, retann):
         return
 
     doc = SphinxDocString(pydoc.getdoc(obj))
-    if doc['Signature']:
-        sig = re.sub(sixu("^[^(]*"), sixu(""), doc['Signature'])
+    sig = doc['Signature'] or getattr(obj, '__text_signature__', None)
+    if sig:
+        sig = re.sub(sixu("^[^(]*"), sixu(""), sig)
         return sig, sixu('')