diff --git a/pillar/api/node_types/__init__.py b/pillar/api/node_types/__init__.py
index ebd9cfce..d6bd585d 100644
--- a/pillar/api/node_types/__init__.py
+++ b/pillar/api/node_types/__init__.py
@@ -7,7 +7,7 @@ _file_embedded_schema = {
     }
 }
 
-ATTACHMENT_SLUG_REGEX = '[a-zA-Z0-9_ ]+'
+ATTACHMENT_SLUG_REGEX = '[a-zA-Z0-9_]+'
 
 attachments_embedded_schema = {
     'type': 'dict',
diff --git a/pillar/cli/maintenance.py b/pillar/cli/maintenance.py
index cfc9db2d..33a4d34e 100644
--- a/pillar/cli/maintenance.py
+++ b/pillar/cli/maintenance.py
@@ -867,6 +867,7 @@ def upgrade_attachment_usage(proj_url=None, all_projects=False, go=False):
                 if status != 200:
                     log.error('Error %i storing altered node %s %s', status, node['_id'], r)
                     raise SystemExit('Error storing node; see log.')
+                log.debug('Updated node %s: %s', node['_id'], r)
 
         log.info('Project %s (%s) has %d nodes with attachments',
                  proj_url, proj_id, node_count)