diff --git a/setup.py b/setup.py
index ba62b18..0fcc83a 100644
--- a/setup.py
+++ b/setup.py
@@ -11,7 +11,7 @@ setup(name='adtwist',
       url='https://github.com/jmgurney/adtwist',
       py_modules=['adtwist'],
       install_requires=[
-          'alarmdecoder',
+          'alarmdecoder==0.12.3',
           'mock',
           'twisted',
           'pyserial',