diff --git a/manual/config/multi_institutions.md b/manual/config/multi_institutions.md
index 7af0db0d..1298c29e 100644
--- a/manual/config/multi_institutions.md
+++ b/manual/config/multi_institutions.md
@@ -12,7 +12,7 @@ In `seahub_settings.py`, add `MULTI_INSTITUTION = True` to enable multi-institut
     )
 ```
 
-!!! tip "Please replease `+=` to `=` if `EXTRA_MIDDLEWARE_CLASSES` or `EXTRA_MIDDLEWARE` is not defined"
+!!! tip "Please replease `+=` to `=` if `EXTRA_MIDDLEWARE` is not defined"
 
 ## Add institutions and institution admins