diff --git a/src/cli/main/__main__.py b/src/cli/main/__main__.py
index e11de9bc..22fc8c54 100644
--- a/src/cli/main/__main__.py
+++ b/src/cli/main/__main__.py
@@ -134,9 +134,10 @@ def _nix_build(
     src: str,
 ) -> List[str]:
     if cache is None:
-        substituters = "https://cache.nixos.org"
+        substituters = "https://cache.nixos.org https://hydra.iohk.io"
         trusted_pub_keys = (
-            "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
+            "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= "
+            "hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= "
         )
     else:
         substituters = " ".join(map(operator.itemgetter("url"), cache))