diff --git a/bob/devtools/bootstrap.py b/bob/devtools/bootstrap.py
index f3762f8262bc3ff1e5ab7a45bf4a6660a061d5a3..18726c4e249e398b332c7e1084dae01e376de34b 100644
--- a/bob/devtools/bootstrap.py
+++ b/bob/devtools/bootstrap.py
@@ -508,7 +508,8 @@ if __name__ == "__main__":
         run_cmdline([conda_bin, "index", conda_bld_path])
         channels, _ = get_channels(
             public=True, stable=True, server=_SERVER, intranet=True, group="bob"
-        ) + ["defaults"]
+        )
+        channels += ["defaults"]
         channels = (
             ["--override-channels"]
             + ["--channel=" + conda_bld_path]