diff --git a/src/components/views/rooms/PresenceLabel.js b/src/components/views/rooms/PresenceLabel.js
index 47a723f5cd..87b218e2e2 100644
--- a/src/components/views/rooms/PresenceLabel.js
+++ b/src/components/views/rooms/PresenceLabel.js
@@ -70,7 +70,7 @@ module.exports = React.createClass({
         if (presence === "online") return _t("Online");
         if (presence === "unavailable") return _t("Idle"); // XXX: is this actually right?
         if (presence === "offline") return _t("Offline");
-        return "Unknown";
+        return _t("Unknown");
     },
 
     render: function() {
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index 8b53f17d8c..f3e4b93e9c 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -881,5 +881,6 @@
     "Failed to remove a user from the summary of %(groupId)s": "Failed to remove a user from the summary of %(groupId)s",
     "The user '%(displayName)s' could not be removed from the summary.": "The user '%(displayName)s' could not be removed from the summary.",
     "Light theme": "Light theme",
-    "Dark theme": "Dark theme"
+    "Dark theme": "Dark theme",
+    "Unknown": "Unknown"
 }