diff --git a/source-builder/sb/build.py b/source-builder/sb/build.py
index e924f62..c868a46 100644
--- a/source-builder/sb/build.py
+++ b/source-builder/sb/build.py
@@ -467,7 +467,7 @@ def get_configs(opts):
         hcp = path.host(path.abspath(cp))
         configs['paths'] += [hcp]
         configs['files'] += _scan(hcp, ['.cfg', '.bset'])
-    configs['files'] = sorted(configs['files'])
+    configs['files'] = sorted(set(configs['files']))
     return configs
 
 def find_config(config, configs):