diff --git a/jedi/builtin.py b/jedi/builtin.py
index 01f8b3f2..85f1f745 100644
--- a/jedi/builtin.py
+++ b/jedi/builtin.py
@@ -352,6 +352,9 @@ def _parse_function_doc(func):
 
     # get full string, parse round parentheses: def func(a, (b,c))
     try:
+        # unbound methods such as pyqtSignals have no __name__
+        if not hasattr(func, "__name__"):
+            return '', 'pass'
         count = 0
         debug.dbg(func, func.__name__, doc)
         start = doc.index('(')