diff --git a/ucs-school-umc-internetrules/umc/python/internetrules/__init__.py b/ucs-school-umc-internetrules/umc/python/internetrules/__init__.py
index 537000a..da71ed6 100644
--- a/ucs-school-umc-internetrules/umc/python/internetrules/__init__.py
+++ b/ucs-school-umc-internetrules/umc/python/internetrules/__init__.py
@@ -140,8 +140,8 @@ class Instance(SchoolBaseModule):
 				raise ValueError(_('The key "%s" needs to be of type: %s') % (ikey, typeStr))
 
 		# validate name
-		if 'name' in iprops and not univention.config_registry.validate_key(iprops['name'].encode('utf-8')):
-			raise ValueError(_('Invalid rule name "%s". The name needs to be a string, the following special characters are not allowed: %s') % (iprops.get('name'), '!, ", §, $, %, &, (, ), [, ], {, }, =, ?, `, +, #, \', ",", ;, <, >, \\'))
+		if 'name' in iprops and not univention.config_registry.validate_key(iprops['name'].encode('utf-8')) or '/' in iprops['name']:
+			raise ValueError(_('Invalid rule name "%s". The name needs to be a string, the following special characters are not allowed: %s') % (iprops.get('name'), '!, ", §, $, %, &, (, ), [, ], {, }, =, ?, `, +, #, \', ",", ;, <, >, \\', '/'))
 
 		# validate type
 		if 'type' in iprops and iprops['type'] not in _filterTypes: