diff --git a/sahara/utils/openstack/images.py b/sahara/utils/openstack/images.py
index 34d7b326..ee4fdbb4 100644
--- a/sahara/utils/openstack/images.py
+++ b/sahara/utils/openstack/images.py
@@ -107,7 +107,7 @@ class SaharaImageManager(images.ImageManager):
         """Adds tags to the specified image."""
         tags = _ensure_tags(tags)
 
-        self.set_meta(image, {PROP_TAG + tag: True for tag in tags})
+        self.set_meta(image, {PROP_TAG + tag: 'True' for tag in tags})
 
     def untag(self, image, tags):
         """Removes tags from the specified image."""