diff --git a/project.py b/project.py
index 43e5c0a..614e7f3 100644
--- a/project.py
+++ b/project.py
@@ -472,7 +472,7 @@ class Project:
         tt_version = self.get_tt_tools_version()
         workflow_url = self.get_workflow_url()
 
-        config = read_config("src/config", ("yaml", "json", "tcl"))
+        config = read_config("src/config", ("json", "tcl"))
         user_config = read_config("src/user_config", ("json",))
         config.update(user_config)
         write_config(config, "src/config_merged", ("json",))