diff --git a/qutebrowser/browser/history.py b/qutebrowser/browser/history.py
index c9609bc03..ca62d9e6c 100644
--- a/qutebrowser/browser/history.py
+++ b/qutebrowser/browser/history.py
@@ -252,10 +252,7 @@ class WebHistory(sql.SqlTable):
                 except ValueError as ex:
                     message.error('Failed to import history: {}'.format(ex))
                 else:
-                    bakpath = path + '.bak'
-                    message.info('History import complete. Moving {} to {}'
-                                 .format(path, bakpath))
-                    os.rename(path, bakpath)
+                    self._write_backup(path)
 
         # delay to give message time to appear before locking down for import
         message.info('Converting {} to sqlite...'.format(path))
@@ -287,6 +284,16 @@ class WebHistory(sql.SqlTable):
         self.insert_batch(data)
         self.completion.insert_batch(completion_data, replace=True)
 
+    def _write_backup(self, path):
+        bak = path + '.bak'
+        message.info('History import complete. Appending {} to {}'
+                     .format(path, bak))
+        with open(path, 'r', encoding='utf-8') as infile:
+            with open(bak, 'a', encoding='utf-8') as outfile:
+                for line in infile:
+                    outfile.write('\n' + line)
+        os.remove(path)
+
     def _format_url(self, url):
         return url.toString(QUrl.RemovePassword | QUrl.FullyEncoded)
 
diff --git a/tests/unit/browser/test_history.py b/tests/unit/browser/test_history.py
index 51157fccb..1454e259b 100644
--- a/tests/unit/browser/test_history.py
+++ b/tests/unit/browser/test_history.py
@@ -284,6 +284,22 @@ def test_import_txt(hist, data_tmpdir, monkeypatch, stubs):
     assert (data_tmpdir / 'history.bak').exists()
 
 
+def test_import_txt_existing_backup(hist, data_tmpdir, monkeypatch, stubs):
+    monkeypatch.setattr(history, 'QTimer', stubs.InstaTimer)
+    histfile = data_tmpdir / 'history'
+    bakfile = data_tmpdir / 'history.bak'
+    histfile.write('12345 http://example.com/ title')
+    bakfile.write('12346 http://qutebrowser.org/')
+
+    hist.import_txt()
+
+    assert list(hist) == [('http://example.com/', 'title', 12345, False)]
+
+    assert not histfile.exists()
+    assert bakfile.read().split('\n') == ['12346 http://qutebrowser.org/',
+                                          '12345 http://example.com/ title']
+
+
 @pytest.mark.parametrize('line', [
     '',
     '#12345 http://example.com/commented',