diff --git a/swh/web/misc/coverage.py b/swh/web/misc/coverage.py
index e710e50980a40385103588d845f41b64aa07d365..d1649a4f4d7cf2ad20b8dfefe7ef57b36e22b256 100644
--- a/swh/web/misc/coverage.py
+++ b/swh/web/misc/coverage.py
@@ -281,7 +281,7 @@ def _get_nixguix_origins_count(origin_url: str) -> int:
     snapshot = archive.lookup_latest_origin_snapshot(origin_url)
     if snapshot:
         snapshot_sizes = archive.lookup_snapshot_sizes(snapshot["id"])
-        return snapshot_sizes["revision"]
+        return snapshot_sizes["release"]
     else:
         return 0