diff --git a/salt/transport/mixins/auth.py b/salt/transport/mixins/auth.py
index dee2001766..16a9be63fa 100644
--- a/salt/transport/mixins/auth.py
+++ b/salt/transport/mixins/auth.py
@@ -419,6 +419,10 @@ class AESReqServerMixin(object):
                 log.debug('Host key change detected in open mode.')
                 with salt.utils.files.fopen(pubfn, 'w+') as fp_:
                     fp_.write(load['pub'])
+            elif not load['pub']:
+                log.error('Public key is empty: {0}'.format(load['id']))
+                return {'enc': 'clear',
+                        'load': {'ret': False}}
 
         pub = None