diff --git a/scripts/metadata2html.py b/scripts/metadata2html.py
index 148a081e..2e27ea3a 100755
--- a/scripts/metadata2html.py
+++ b/scripts/metadata2html.py
@@ -74,7 +74,7 @@ def import_config(configfile, logger):
 def get_metadata_files_from_config(config, logger):
     """Create a list of metadata filenames for a CCPP prebuild configuration"""
     filenames = []
-    for sourcefile in config['variable_definition_files'] + config['scheme_files'].keys():
+    for sourcefile in config['variable_definition_files'] + config['scheme_files']:
         metafile = os.path.splitext(sourcefile)[0]+'.meta'
         if os.path.isfile(metafile):
             filenames.append(metafile)