diff --git a/test_externalfailures.py b/test_externalfailures.py
index 7521532..e084a53 100644
--- a/test_externalfailures.py
+++ b/test_externalfailures.py
@@ -30,7 +30,7 @@ class TestZfsNode(unittest2.TestCase):
 
         #free up space
         r=shelltest("rm /test_target1/waste")
-        r=shelltest("zpool sync")
+        r=shelltest("zfs umount test_target1")
 
         #should resume and succeed
         with io.StringIO() as buf:
diff --git a/test_zfsautobackup.py b/test_zfsautobackup.py
index 64fb58b..f2963e7 100644
--- a/test_zfsautobackup.py
+++ b/test_zfsautobackup.py
@@ -1,5 +1,7 @@
 from basetest import *
 import time
+import contextlib
+import io
 
 
 
@@ -11,6 +13,19 @@ class TestZfsAutobackup(unittest2.TestCase):
 
     def  test_defaults(self):
 
+        with self.subTest("no datasets selected"):
+            #should resume and succeed
+            
+            with io.StringIO() as buf:
+                with contextlib.redirect_stderr(buf):
+                    with patch('time.strftime', return_value="20101111000000"):
+                        self.assertTrue(ZfsAutobackup("nonexisting test_target1 --verbose --debug".split(" ")).run())
+
+                print(buf.getvalue())
+                #did we really resume?
+                self.assertIn("No source filesystems selected", buf.getvalue())
+
+
         with self.subTest("defaults with full verbose and debug"):
 
             with patch('time.strftime', return_value="20101111000000"):