diff --git a/kadmos/cmdows/cmdows.py b/kadmos/cmdows/cmdows.py
index d1ef5e03c8fff63f9ae630a3a173fb6f606ca39d..f07e35b57e94a89db2c7cda2143c17b9140813b1 100644
--- a/kadmos/cmdows/cmdows.py
+++ b/kadmos/cmdows/cmdows.py
@@ -37,6 +37,7 @@ class CMDOWS(object):
         self.XMLNS_PREFIX = 'https://bitbucket.org/imcovangent/cmdows/raw/master/schema/'
         self.XMLNS_SUFFIX = '/cmdows.xsd'
         if file_path:
+            assert os.path.isfile(file_path), 'File {} does not seem to exist.'.format(file_path)
             self.file = file_path
         if element is not None:
             self.root = ElementTree(element).getroot()