diff --git a/setup.py b/setup.py
index 339d3c1..d71adf8 100644
--- a/setup.py
+++ b/setup.py
@@ -78,7 +78,7 @@
     # your project is installed. For an analysis of "install_requires" vs pip's
     # requirements files see:
     # https://packaging.python.org/en/latest/requirements.html
-    install_requires=['pypyr', 'boto3', 'ruamel.yaml'],
+    install_requires=['pypyr', 'boto3', 'ruamel.yaml<0.15'],
 
     # List additional groups of dependencies here (e.g. development
     # dependencies). You can install these using the following syntax,