diff --git a/swh/loader/package/opam/loader.py b/swh/loader/package/opam/loader.py
--- a/swh/loader/package/opam/loader.py
+++ b/swh/loader/package/opam/loader.py
@@ -165,6 +165,7 @@
                     "--reinit",
                     "--bare",
                     "--no-setup",
+                    "--yes",
                     "--root",
                     self.opam_root,
                     self.opam_instance,