diff --git a/js/ui/endSessionDialog.js b/js/ui/endSessionDialog.js
index a7db08807..f4950ba84 100644
--- a/js/ui/endSessionDialog.js
+++ b/js/ui/endSessionDialog.js
@@ -231,14 +231,13 @@ class EndSessionDialog extends ModalDialog.ModalDialog {
         this._loginManager = LoginManager.getLoginManager();
         this._userManager = AccountsService.UserManager.get_default();
         this._user = this._userManager.get_user(GLib.get_user_name());
+        this._updatesPermission = null;
 
         this._pkOfflineProxy = new PkOfflineProxy(Gio.DBus.system,
                                                   'org.freedesktop.PackageKit',
                                                   '/org/freedesktop/PackageKit',
-                                                  (proxy, error) => {
-                                                      if (error)
-                                                          log(error.message);
-                                                  });
+                                                  this._onPkOfflineProxyCreated.bind(this));
+
         this._powerProxy = new UPowerProxy(Gio.DBus.system,
                                            'org.freedesktop.UPower',
                                            '/org/freedesktop/UPower',
@@ -333,16 +332,33 @@ class EndSessionDialog extends ModalDialog.ModalDialog {
         this._inhibitorSection.add_actor(this._sessionHeader);
         this._inhibitorSection.add_actor(this._sessionList);
 
-        try {
-            this._updatesPermission = Polkit.Permission.new_sync("org.freedesktop.packagekit.trigger-offline-update", null, null);
-        } catch (e) {
-            log('No permission to trigger offline updates: %s'.format(e.toString()));
-        }
-
         this._dbusImpl = Gio.DBusExportedObject.wrapJSObject(EndSessionDialogIface, this);
         this._dbusImpl.export(Gio.DBus.session, '/org/gnome/SessionManager/EndSessionDialog');
     }
 
+    _onPkOfflineProxyCreated(proxy, error) {
+        if (error) {
+            log(error.message);
+            return;
+        }
+
+        // Creating a D-Bus proxy won't propagate SERVICE_UNKNOWN or NAME_HAS_NO_OWNER
+        // errors if PackageKit is not available, but the GIO implementation will make
+        // sure in that case that the proxy's g-name-owner is set to null, so check that.
+        if (this._pkOfflineProxy.g_name_owner === null) {
+            this._pkOfflineProxy = null;
+            return;
+        }
+
+        // It only makes sense to check for this permission if PackageKit is available.
+        try {
+            this._updatesPermission = Polkit.Permission.new_sync(
+                "org.freedesktop.packagekit.trigger-offline-update", null, null);
+        } catch(e) {
+            log('No permission to trigger offline updates: %s'.format(e.toString()));
+        }
+    }
+
     _onDestroy() {
         this._user.disconnect(this._userLoadedId);
         this._user.disconnect(this._userChangedId);
@@ -387,7 +403,8 @@ class EndSessionDialog extends ModalDialog.ModalDialog {
         }
 
         // Use a different description when we are installing a system upgrade
-        if (dialogContent.upgradeDescription) {
+        // if the PackageKit proxy is available (i.e. PackageKit is available).
+        if (this._pkOfflineProxy && dialogContent.upgradeDescription) {
             let name = this._pkOfflineProxy.PreparedUpgrade['name'].deep_unpack();
             let version = this._pkOfflineProxy.PreparedUpgrade['version'].deep_unpack();
 
@@ -496,6 +513,12 @@ class EndSessionDialog extends ModalDialog.ModalDialog {
     }
 
     _triggerOfflineUpdateReboot(callback) {
+        // Handle this gracefully if PackageKit is not available.
+        if (!this._pkOfflineProxy) {
+            callback();
+            return;
+        }
+
         this._pkOfflineProxy.TriggerRemote('reboot', (result, error) => {
             if (error)
                 log(error.message);
@@ -505,6 +528,12 @@ class EndSessionDialog extends ModalDialog.ModalDialog {
     }
 
     _triggerOfflineUpdateShutdown(callback) {
+        // Handle this gracefully if PackageKit is not available.
+        if (!this._pkOfflineProxy) {
+            callback();
+            return;
+        }
+
         this._pkOfflineProxy.TriggerRemote('power-off', (result, error) => {
             if (error)
                 log(error.message);
@@ -514,6 +543,12 @@ class EndSessionDialog extends ModalDialog.ModalDialog {
     }
 
     _triggerOfflineUpdateCancel(callback) {
+        // Handle this gracefully if PackageKit is not available.
+        if (!this._pkOfflineProxy) {
+            callback();
+            return;
+        }
+
         this._pkOfflineProxy.CancelRemote((result, error) => {
             if (error)
                 log(error.message);
@@ -676,7 +711,8 @@ class EndSessionDialog extends ModalDialog.ModalDialog {
         this._totalSecondsToStayOpen = totalSecondsToStayOpen;
         this._type = type;
 
-        if (this._type == DialogType.RESTART) {
+        // Only consider updates and upgrades if PackageKit is available.
+        if (this._pkOfflineProxy && this._type == DialogType.RESTART) {
             if (this._pkOfflineProxy.UpdateTriggered)
                 this._type = DialogType.UPDATE_RESTART;
             else if (this._pkOfflineProxy.UpgradeTriggered)
@@ -708,8 +744,9 @@ class EndSessionDialog extends ModalDialog.ModalDialog {
         if (dialogContent.showOtherSessions)
             this._loadSessions();
 
-        let updateTriggered = this._pkOfflineProxy.UpdateTriggered;
-        let updatePrepared = this._pkOfflineProxy.UpdatePrepared;
+        // Only consider updates and upgrades if PackageKit is available.
+        let updateTriggered = this._pkOfflineProxy ? this._pkOfflineProxy.UpdateTriggered : false;
+        let updatePrepared = this._pkOfflineProxy ? this._pkOfflineProxy.UpdatePrepared : false;
         let updatesAllowed = this._updatesPermission && this._updatesPermission.allowed;
 
         _setCheckBoxLabel(this._checkBox, dialogContent.checkBoxText || '');