diff --git a/js/ui/extensionSystem.js b/js/ui/extensionSystem.js
index 3bd0cbe31..364d10662 100644
--- a/js/ui/extensionSystem.js
+++ b/js/ui/extensionSystem.js
@@ -16,6 +16,7 @@ const ExtensionState = {
     DISABLED: 2,
     ERROR: 3,
     OUT_OF_DATE: 4,
+    DOWNLOADING: 5,
 
     // Used as an error state for operations on unknown extensions,
     // should never be in a real extensionMeta object.
@@ -113,6 +114,12 @@ function installExtensionFromManifestURL(uuid, url) {
                 return;
             }
 
+            let meta = extensionMeta[uuid] = { uuid: uuid,
+                                               state: ExtensionState.DOWNLOADING,
+                                               error: '' };
+
+            _signals.emit('extension-state-changed', meta);
+
             installExtensionFromManifest(manifest, meta);
         });
 }
diff --git a/js/ui/lookingGlass.js b/js/ui/lookingGlass.js
index 03830c2e7..c646d6166 100644
--- a/js/ui/lookingGlass.js
+++ b/js/ui/lookingGlass.js
@@ -690,6 +690,8 @@ Extensions.prototype = {
                 return _("Error");
             case ExtensionSystem.ExtensionState.OUT_OF_DATE:
                 return _("Out of date");
+            case ExtensionSystem.ExtensionState.DOWNLOADING:
+                return _("Downloading");
         }
         return 'Unknown'; // Not translated, shouldn't appear
     },