diff --git a/en_US/howto/sogo.manage.resources.md b/en_US/howto/sogo.manage.resources.md
index 7d3e05b8..b9de99c3 100644
--- a/en_US/howto/sogo.manage.resources.md
+++ b/en_US/howto/sogo.manage.resources.md
@@ -55,9 +55,10 @@ below:
 # this line already exists
 include /etc/openldap/schema/iredmail.schema
 
-# Add below 2 new lines
-include /etc/openldap/schema/calresource.schema
+# Add below 2 new lines.
+# WARNING: calentry.schema must be loaded before calresource.schema.
 include /etc/openldap/schema/calentry.schema
+include /etc/openldap/schema/calresource.schema
 ```
 
 Since we don't use any new ldap attribute names in LDAP query filter, no index
diff --git a/html/sogo.manage.resources.html b/html/sogo.manage.resources.html
index 3dee4951..67496e0f 100644
--- a/html/sogo.manage.resources.html
+++ b/html/sogo.manage.resources.html
@@ -78,9 +78,10 @@ below:</p>
 <pre><code># this line already exists
 include /etc/openldap/schema/iredmail.schema
 
-# Add below 2 new lines
-include /etc/openldap/schema/calresource.schema
+# Add below 2 new lines.
+# WARNING: calentry.schema must be loaded before calresource.schema.
 include /etc/openldap/schema/calentry.schema
+include /etc/openldap/schema/calresource.schema
 </code></pre>
 
 <p>Since we don't use any new ldap attribute names in LDAP query filter, no index