diff --git a/tests/unit/test_app.py b/tests/unit/test_app.py
new file mode 100644
index 000000000..7f40cb891
--- /dev/null
+++ b/tests/unit/test_app.py
@@ -0,0 +1,40 @@
+# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:
+
+# Copyright 2016 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
+#
+# This file is part of qutebrowser.
+#
+# qutebrowser is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# qutebrowser is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with qutebrowser.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Tests for the qutebrowser.app module."""
+
+from PyQt5.QtCore import QBuffer
+
+from qutebrowser import app
+
+def test_on_focus_changed_issue1484(monkeypatch, qapp, caplog):
+    """Check what happens when on_focus_changed is called with wrong args.
+
+    For some reason, Qt sometimes calls on_focus_changed() with a QBuffer as
+    argument. Let's make sure we handle that gracefully.
+    """
+    monkeypatch.setattr(app, 'qApp', qapp)
+
+    buf = QBuffer()
+    app.on_focus_changed(buf, buf)
+
+    assert len(caplog.records) == 1
+    record = caplog.records[0]
+    expected = "on_focus_changed called with non-QWidget {!r}".format(buf)
+    assert record.message == expected