diff --git a/documentation/conf.py b/documentation/conf.py
index 8df488166df3cbd642f3b7f1ad83493ab68efce4..b0a15a6f281ce7008fea14840657803c94f7b6ae 100644
--- a/documentation/conf.py
+++ b/documentation/conf.py
@@ -27,6 +27,7 @@ def configureDoxyLayout(template_file, output_file, page_url, page_tile):
 
 read_the_docs_build = os.environ.get('READTHEDOCS', None) == 'True'
 build_version = os.environ.get('READTHEDOCS_VERSION', None)
+breathe_projects = {}
 
 doc_url = 'https://corsika-8.readthedocs.io/en/'+build_version