diff --git a/doc/sphinx/_doclib/development.rst b/doc/sphinx/_doclib/development.rst
index d41b0a7e242989ff12748d9916178de0202ae791..4ba6156311485fedc3902bd285699243cb625887 100644
--- a/doc/sphinx/_doclib/development.rst
+++ b/doc/sphinx/_doclib/development.rst
@@ -475,6 +475,12 @@ target will be very handy to you:
 Database schema migrations
 --------------------------------------------------------------------------------
 
+In case you use some extensions, you should use "create extension" and
+"drop extension", possibly with "on conflict ignore" or something like
+that to not drop extension if it is already enabled and has some other
+uses by administrator.
+
+
 Event database migrations
 ````````````````````````````````````````````````````````````````````````````````