diff --git a/builder/py/retrobuilder/model.py b/builder/py/retrobuilder/model.py
index ffd20c5..4455093 100644
--- a/builder/py/retrobuilder/model.py
+++ b/builder/py/retrobuilder/model.py
@@ -27,8 +27,8 @@ class ModuleSpec:
 
 @dataclass(frozen=True)
 class BaseSpec(ModuleSpec):
-    BASE__REPO_URL: str = "http://archive.debian.org/debian/"
-    BASE__SECURITY_REPO_URL: str = "http://archive.debian.org/debian-security/"
+    REPO_URL: str = "http://archive.debian.org/debian/"
+    SECURITY_REPO_URL: str = "http://archive.debian.org/debian-security/"
 
 
 @dataclass(frozen=True)