diff --git a/desktop/org.gnome.Geary.appdata.xml.in.in b/desktop/org.gnome.Geary.appdata.xml.in.in
index 1668d62b..8a391ff4 100644
--- a/desktop/org.gnome.Geary.appdata.xml.in.in
+++ b/desktop/org.gnome.Geary.appdata.xml.in.in
@@ -260,4 +260,9 @@
     <display_length compare="ge">360</display_length>
   </requires>
 
+  <custom>
+    <value key="Purism::form_factor">workstation</value>
+    <value key="Purism::form_factor">mobile</value>
+  </custom>
+
 </component>
diff --git a/desktop/org.gnome.Geary.desktop.in.in b/desktop/org.gnome.Geary.desktop.in.in
index 81fa2537..298abb17 100644
--- a/desktop/org.gnome.Geary.desktop.in.in
+++ b/desktop/org.gnome.Geary.desktop.in.in
@@ -16,6 +16,7 @@ StartupNotify=true
 DBusActivatable=true
 Actions=compose;new-window
 X-GNOME-UsesNotifications=true
+# Translators: Do NOT translate or transliterate this text (these are enum types)!
 X-Purism-FormFactor=Workstation;Mobile;
 
 [Desktop Action compose]