diff --git a/plugins/builder/save_failed_tree.py b/plugins/builder/save_failed_tree.py
index d1b618a6..f5fec8a2 100644
--- a/plugins/builder/save_failed_tree.py
+++ b/plugins/builder/save_failed_tree.py
@@ -2,6 +2,8 @@ import fnmatch
 import os
 import tarfile
 import ConfigParser
+
+import koji
 import koji.tasks as tasks
 from __main__ import BuildRoot
 
@@ -38,7 +40,10 @@ class SaveFailedTreeTask(tasks.BaseTaskHandler):
         read_config()
         tar_path = os.path.join(self.workdir, 'broots-task-%s.tar.gz' % taskID)
         f = tarfile.open(tar_path, "w:gz")
+        host_id = self.session.host.getHost()['id']
         for broot in self.session.listBuildroots(taskID=taskID):
+            if broot['host_id'] != host_id:
+                raise koji.GenericError("Task is run on wrong builder.")
             broot = BuildRoot(self.session, self.options, broot['id'])
             path = broot.rootdir()
             if full:
diff --git a/tests/test_plugins/test_save_failed_tree_builder.py b/tests/test_plugins/test_save_failed_tree_builder.py
new file mode 100644
index 00000000..76dedf9c
--- /dev/null
+++ b/tests/test_plugins/test_save_failed_tree_builder.py
@@ -0,0 +1,113 @@
+import mock
+import os
+import sys
+import unittest
+
+# alter pythonpath to not load hub plugin
+sys.path = [os.path.join(os.path.dirname(__file__), '../../plugins/builder')] + sys.path
+#raise(Exception(sys.path))
+
+import koji
+# inject builder data
+from tests.test_builder.loadkojid import kojid
+import __main__
+__main__.BuildRoot = kojid.BuildRoot
+
+from save_failed_tree import SaveFailedTreeTask
+
+class TestSaveFailedTree(unittest.TestCase):
+    def setUp(self):
+        self.session = mock.MagicMock()
+        self.session.host.getHost.return_value = {'id': 1}
+        options = mock.MagicMock()
+        options.workdir = '/tmp/nonexistentdirectory'
+        options.mockdir = '/tmp/mockdir'
+        options.name = 'name'
+        self.t = SaveFailedTreeTask(123, 'saveFailedTree', {}, self.session, options)
+
+    @mock.patch('os.unlink')
+    @mock.patch('tarfile.open')
+    def testNonExistentTask(self, tarfile, os_unlink):
+        # empty tarball
+        tfile = mock.MagicMock(name='tfile')
+        tarfile.return_value = tfile
+
+        self.t.handler(1)
+
+        tarfile.assert_called_once_with(
+            '/tmp/nonexistentdirectory/tasks/123/123/broots-task-1.tar.gz',
+            'w:gz'
+        )
+        tfile.add.assert_not_called()
+        tfile.close.assert_called_once_with()
+        os_unlink.assert_called_once_with('/tmp/nonexistentdirectory/tasks/123/123/broots-task-1.tar.gz')
+
+    @mock.patch('os.unlink')
+    @mock.patch('tarfile.open')
+    def testCorrect(self, tarfile, os_unlink):
+        def getBuildroot(bid):
+            tmp = {
+                'tag_name': 'tag_name',
+                'repo_id': 'repo_id',
+            }
+            if bid == 1:
+                tmp['task_id'] = 1000
+                tmp['arch'] = 'x86_64'
+                tmp['tag_id'] = 5000
+            elif bid == 2:
+                tmp['task_id'] = 1001
+                tmp['arch'] = 'i386'
+                tmp['tag_id'] = 5001
+            return tmp
+
+        self.session.getBuildroot.side_effect = getBuildroot
+        tfile = mock.MagicMock(name='tfile')
+        tfile.add = mock.MagicMock()
+        tarfile.return_value = tfile
+        # simplified return values, only id should be used
+        self.session.listBuildroots.return_value = [{'id': 1, 'host_id': 1}, {'id': 2, 'host_id': 1}]
+
+        self.t.handler(1)
+
+        tarfile.assert_called_once_with(
+            '/tmp/nonexistentdirectory/tasks/123/123/broots-task-1.tar.gz',
+            'w:gz'
+        )
+        self.assertEqual(tfile.add.call_args_list[0][0][0], '/tmp/mockdir/tag_name-1-repo_id/root/builddir')
+        self.assertEqual(tfile.add.call_args_list[1][0][0], '/tmp/mockdir/tag_name-2-repo_id/root/builddir')
+        self.assertEqual(len(tfile.add.call_args_list), 2)
+        tfile.close.assert_called_once_with()
+        os_unlink.assert_called_once_with('/tmp/nonexistentdirectory/tasks/123/123/broots-task-1.tar.gz')
+
+    @mock.patch('os.unlink')
+    @mock.patch('tarfile.open')
+    def testWrongBuilder(self, tarfile, os_unlink):
+        def getBuildroot(bid):
+            tmp = {
+                'tag_name': 'tag_name',
+                'repo_id': 'repo_id',
+            }
+            if bid == 1:
+                tmp['task_id'] = 1000
+                tmp['arch'] = 'x86_64'
+                tmp['tag_id'] = 5000
+            elif bid == 2:
+                tmp['task_id'] = 1001
+                tmp['arch'] = 'i386'
+                tmp['tag_id'] = 5001
+            return tmp
+
+        self.session.getBuildroot.side_effect = getBuildroot
+        tfile = mock.MagicMock(name='tfile')
+        tarfile.return_value = tfile
+        # simplified return values, only id should be used
+        self.session.listBuildroots.return_value = [{'id': 1, 'host_id': 2}, {'id': 2, 'host_id': 2}]
+
+        with self.assertRaises(koji.GenericError):
+            self.t.handler(1)
+
+    def testFull(self):
+        pass
+
+    def testFailUpload(self):
+        pass