diff --git a/lib/ansible/inventory/__init__.py b/lib/ansible/inventory/__init__.py
index 69f520cdd3e..4d866587daf 100644
--- a/lib/ansible/inventory/__init__.py
+++ b/lib/ansible/inventory/__init__.py
@@ -34,6 +34,7 @@ from ansible.inventory.dir import InventoryDirectory, get_file_parser
 from ansible.inventory.group import Group
 from ansible.inventory.host import Host
 from ansible.plugins import vars_loader
+from ansible.utils.unicode import to_unicode
 from ansible.utils.vars import combine_vars
 from ansible.parsing.utils.addresses import parse_address
 
@@ -173,9 +174,9 @@ class Inventory(object):
 
         if not ignore_limits_and_restrictions:
             if self._subset:
-                pattern_hash += u":%s" % self._subset
+                pattern_hash += u":%s" % to_unicode(self._subset)
             if self._restriction:
-                pattern_hash += u":%s" % self._restriction
+                pattern_hash += u":%s" % to_unicode(self._restriction)
 
         if pattern_hash in HOSTS_PATTERNS_CACHE:
             return HOSTS_PATTERNS_CACHE[pattern_hash][:]