diff --git a/cloud/amazon/iam_cert.py b/cloud/amazon/iam_cert.py
index d8934864e5e..8e56017052e 100644
--- a/cloud/amazon/iam_cert.py
+++ b/cloud/amazon/iam_cert.py
@@ -232,7 +232,7 @@ def main():
         new_name=dict(default=None, required=False),
         path=dict(default='/', required=False),
         new_path=dict(default=None, required=False),
-        dup_ok=dict(default=False, required=False, choices=[False, True])
+        dup_ok=dict(default=False, required=False, choices=[False, True], type='bool')
     )
     )