diff --git a/lib/ansible/plugins/action/synchronize.py b/lib/ansible/plugins/action/synchronize.py
index 2bb5b7c7863..889579943d4 100644
--- a/lib/ansible/plugins/action/synchronize.py
+++ b/lib/ansible/plugins/action/synchronize.py
@@ -49,7 +49,7 @@ class ActionModule(ActionBase):
         return path
 
     def _host_is_ipv6_address(self, host):
-        return ':' in host
+        return ':' in to_text(host, errors='surrogate_or_strict')
 
     def _format_rsync_rsh_target(self, host, path, user):
         ''' formats rsync rsh target, escaping ipv6 addresses if needed '''