diff --git a/icons/tryton-lock.svg b/icons/tryton-lock.svg
new file mode 100644
index 0000000..74ee5f0
--- /dev/null
+++ b/icons/tryton-lock.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24"><path d="M0 0h24v24H0z" fill="none"/><path d="M18 8h-1V6c0-2.76-2.24-5-5-5S7 3.24 7 6v2H6c-1.1 0-2 .9-2 2v10c0 1.1.9 2 2 2h12c1.1 0 2-.9 2-2V10c0-1.1-.9-2-2-2zm-6 9c-1.1 0-2-.9-2-2s.9-2 2-2 2 .9 2 2-.9 2-2 2zm3.1-9H8.9V6c0-1.71 1.39-3.1 3.1-3.1 1.71 0 3.1 1.39 3.1 3.1v2z"/></svg>
\ No newline at end of file
diff --git a/invoice.xml b/invoice.xml
index 4fa25e0..77835d0 100644
--- a/invoice.xml
+++ b/invoice.xml
@@ -66,5 +66,11 @@
             <field name="model">account.invoice,-1</field>
             <field name="action" ref="wizard_generate_signed_facturae"/>
         </record>-->
+
+        <record model="ir.ui.icon" id="lock_icon">
+            <field name="name">tryton-lock</name>
+            <field name="path">icons/tryton-lock.svg</name>
+        </record>
+
     </data>
 </tryton>