diff --git a/ucs-school-import/modules/ucsschool/importer/utils/username_handler.py b/ucs-school-import/modules/ucsschool/importer/utils/username_handler.py
index b30c101..120b618 100644
--- a/ucs-school-import/modules/ucsschool/importer/utils/username_handler.py
+++ b/ucs-school-import/modules/ucsschool/importer/utils/username_handler.py
@@ -42,13 +42,14 @@ from ucsschool.importer.utils.logging import get_logger
 
 
 class UsernameHandler(object):
-	replacement_variable_pattern = re.compile(r"\[.*?\]")
+
 	allowed_chars = string.ascii_letters + string.digits + "."
 
 	def __init__(self, username_max_length):
 		self.username_max_length = username_max_length
 		self.logger = get_logger()
 		self.connection, self.position = get_admin_connection()
+		self.replacement_variable_pattern = re.compile(r'\[(%s)\]' % '|'.join(map(re.escape, self.counter_variable_to_function.keys())))
 
 	def add_to_ldap(self, username, first_number):
 		assert isinstance(username, basestring)