diff --git a/lib/ceph/__init__.py b/lib/ceph/__init__.py
index 4afe5eb..b95a826 100644
--- a/lib/ceph/__init__.py
+++ b/lib/ceph/__init__.py
@@ -949,7 +949,7 @@ def get_mds_bootstrap_key():
 
 
 _default_caps = collections.OrderedDict([
-    ('mon', ['allow rw']),
+    ('mon', ['allow r']),
     ('osd', ['allow rwx']),
 ])