diff --git a/doc/repmgr-standby-promote.xml b/doc/repmgr-standby-promote.xml
index 72be9595..213b447b 100644
--- a/doc/repmgr-standby-promote.xml
+++ b/doc/repmgr-standby-promote.xml
@@ -115,7 +115,12 @@
       function must be granted with e.g.:
       <programlisting>
     GRANT EXECUTE ON FUNCTION pg_catalog.pg_promote TO repmgr</programlisting>
-    </para>
+      </para>
+      <para>
+        Note that permissions are only effective for the database they are granted in, so
+        this <emphasis>must</emphasis> be executed in the &repmgr; database to be effective.
+      </para>
+
     <para>
       A future &repmgr; release will relax this restriction by falling back to
       <command>pg_ctl promote</command>, as used for pre-PostgreSQL 12 versions.