diff --git a/keystoneclient/middleware/auth_token.py b/keystoneclient/middleware/auth_token.py
index 8aa801dde..eba0093b6 100644
--- a/keystoneclient/middleware/auth_token.py
+++ b/keystoneclient/middleware/auth_token.py
@@ -1262,6 +1262,7 @@ class AuthProtocol(object):
                                           self.signing_ca_file_name):
                     self.fetch_ca_cert()
                     continue
+                self.LOG.error('CMS Verify output: %s', err.output)
                 raise
             except cms.subprocess.CalledProcessError as err:
                 self.LOG.warning('Verify error: %s', err)