diff --git a/bob/devtools/bootstrap.py b/bob/devtools/bootstrap.py
index 73712a948b60098f559ef2200a204f1149a9cf07..c0d59cdfc73377f5377a144625dad60444563588 100644
--- a/bob/devtools/bootstrap.py
+++ b/bob/devtools/bootstrap.py
@@ -533,7 +533,7 @@ if __name__ == "__main__":
                 intranet=True,
                 group="bob",
             )
-            + ["defaults"]
+            + ("defaults",)
         )
         channels = ["--override-channels"] + ["--channel=%s" % k for k in channels]
         conda_cmd = "install" if args.envname in ("base", "root") else "create"