diff --git a/addons/plugin_thunderbird/plugin_thunderbird.xml b/addons/plugin_thunderbird/plugin_thunderbird.xml
index 86e63762eba..0ce6a053554 100644
--- a/addons/plugin_thunderbird/plugin_thunderbird.xml
+++ b/addons/plugin_thunderbird/plugin_thunderbird.xml
@@ -23,7 +23,7 @@
                             <field name="pdf_file" widget="url"/>
                         </group>
                         <separator string="Installation and Configuration Steps"/>
-                        <p>Thunderbird plugin installation:</p>
+                        <p>Thunderbird plug-in installation:</p>
                         <ol>
                             <li> Save the Thunderbird plug-in.</li>
                             <li> From the Thunderbird menubar: Tools ­> Add-ons -> Screwdriver/Wrench Icon -> Install add-on from file...</li>