diff --git a/local_extensions.py b/local_extensions.py
index f7f438c..d7235d4 100644
--- a/local_extensions.py
+++ b/local_extensions.py
@@ -42,7 +42,7 @@ def __init__(self, environment):
 #
 
 def _modname(data):
-    return data["project_slug"].replace("-", "")
+    return data["project_slug"].replace("-", "_")
 
 
 def _is_github(data):