diff -r be50d98d3668 -r d7c015d8c6c0 tests/subfiles.py
--- a/tests/subfiles.py	Wed Jan 31 14:54:58 2018 +0200
+++ b/tests/subfiles.py	Wed Jan 31 14:57:09 2018 +0200
@@ -6,7 +6,7 @@
 ini_path = Path(dirname(__file__)) / 'library-standards.ini'
 library_standards = ConfigParser()
 
-with open(ini_path) as file:
+with open(str(ini_path)) as file:
     library_standards.read_file(file)
 
 def determinant_test(model):