diff --git a/UPGRADING b/UPGRADING
index c0866e5e..6d9f3cf2 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -1,6 +1,13 @@
 Upgrading
 =========
 
+From 1.9.0 to 1.9.1
+-------------------
+
+1. Merge "web/lib/config.inc.php.proto" with "web/lib/config.inc.php".
+
+2. Install translations by running `make install` in "po/".
+
 From 1.8.2 to 1.9.0
 -------------------