diff --git a/lib/spack/spack/stage.py b/lib/spack/spack/stage.py
index d730fd63b4e..dd381fd4029 100644
--- a/lib/spack/spack/stage.py
+++ b/lib/spack/spack/stage.py
@@ -502,6 +502,7 @@ def cache_mirror(self, stats):
             stats.already_existed(absolute_storage_path)
         else:
             self.fetch()
+            self.check()
             spack.caches.mirror_cache.store(
                 self.fetcher, self.mirror_paths.storage_path)
             stats.added(absolute_storage_path)