diff --git a/src/cryptobox/tests/test.core.blockdevice.py b/src/cryptobox/tests/test.core.blockdevice.py
index f65e323..061b8b1 100755
--- a/src/cryptobox/tests/test.core.blockdevice.py
+++ b/src/cryptobox/tests/test.core.blockdevice.py
@@ -51,7 +51,8 @@ class CoreBlockDevice(CommonTestClass):
         blockdevice_found = False
         for sys_dir, dev_node, parent, major_minor in COMMON_DEV_INFOS:
             if os.path.isdir(sys_dir):
-                self.assertTrue(func(dev_node).devnum == major_minor)
+                self.assertTrue(func(dev_node).major == major_minor[0])
+                self.assertTrue(func(dev_node).minor == major_minor[1])
                 blockdevice_found = True
         # we assume, that we found at least one blockdevice
         self.assertTrue(blockdevice_found)