diff --git a/src/kyupy/techlib.py b/src/kyupy/techlib.py
index df20268..21c82a6 100644
--- a/src/kyupy/techlib.py
+++ b/src/kyupy/techlib.py
@@ -44,7 +44,7 @@ class TechLib:
                                     ('SDFF', ('D',), 0),
                                     ('SDFF', ('QN',), 1),
                                     ('SDFF', ('CLK',), 3),
-                                    ('SDFF', ('RSTB',), 4),
+                                    ('SDFF', ('RSTB', 'RN'), 4),
                                     ('SDFF', ('SETB',), 5)]:
             if kind.startswith(prefix) and pin in pins: return index
         for index, pins in enumerate([('A1', 'IN1', 'A', 'S', 'INP', 'I', 'Q', 'QN', 'Y', 'Z', 'ZN'),