diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index e04f842..18abc40 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -18,6 +18,8 @@ jobs:
             # currently there is no way to nix copy to use the flake settings so we need them
             substituters = https://cache.tcp4.me?priority=99
             trusted-public-keys = cache.tcp4.me:cmk2Iz81lQuX7FtTUcBgtqgI70E8p6SOamNAIcFDSew=
+            # if substituters fail, build it again
+            fallback = true
       - uses: webfactory/ssh-agent@v0.8.0
         with:
           ssh-private-key: ${{ secrets.BUILDER_TOKEN }}