diff --git a/setup.py b/setup.py
index 5909b90..d6c42d6 100644
--- a/setup.py
+++ b/setup.py
@@ -11,6 +11,6 @@ setup(
     packages=find_packages(),
     include_package_data=True,
     install_requires=[
-        'pyyaml==4.*'
+        'pyyaml==3.*'
     ]
 )