diff --git a/unittests/test_configuration.py b/unittests/test_configuration.py
index 9522e58c735b1c7e0efd6d029fe41c9e4e71088a..40506e878b18473587da8b694d9381c15bdbd860 100644
--- a/unittests/test_configuration.py
+++ b/unittests/test_configuration.py
@@ -22,10 +22,11 @@
 # ** end header
 #
 
-import pytest
-import linkahead as db
 from os import environ, getcwd, remove
 from os.path import expanduser, isfile, join
+
+import linkahead as db
+import pytest
 from pytest import raises
 
 
@@ -55,7 +56,8 @@ def test_config_ini_via_envvar(temp_ini_files):
     environ["PYCAOSDBINI"] = "bla bla"
     assert environ["PYCAOSDBINI"] == "bla bla"
     # test wrong configuration file in envvar
-    assert not expanduser(environ["PYCAOSDBINI"]) in db.configuration._read_config_files()
+    with pytest.raises(RuntimeError):
+        db.configuration._read_config_files()
     # test good configuration file in envvar
     environ["PYCAOSDBINI"] = "~/.pylinkahead.ini"
     assert expanduser("~/.pylinkahead.ini") in db.configuration._read_config_files()