diff --git a/mayan/settings/base.py b/mayan/settings/base.py
index 115e58ca0e..2950fd3e74 100644
--- a/mayan/settings/base.py
+++ b/mayan/settings/base.py
@@ -58,6 +58,7 @@ INSTALLED_APPS = (
     'corsheaders',
     'djcelery',
     'formtools',
+    'mathfilters',
     'mptt',
     'pure_pagination',
     'rest_framework',