diff --git a/beat/web/libraries/__init__.py b/beat/web/libraries/__init__.py
index 3e7198cc7785c7da9bbec494fb34931622dbb90b..7f31614a3180f10e77a28dfd2cd68f230c62035a 100644
--- a/beat/web/libraries/__init__.py
+++ b/beat/web/libraries/__init__.py
@@ -25,4 +25,4 @@
 #                                                                             #
 ###############################################################################
 
-default_app_config = 'beat.web.libraries.apps.LibrariesConfig'
+default_app_config = "beat.web.libraries.apps.LibrariesConfig"