diff --git a/flake.nix b/flake.nix
index 4e902a4cd..042f68e44 100644
--- a/flake.nix
+++ b/flake.nix
@@ -87,9 +87,6 @@
         };
         cargoLock = {
           lockFile = ./Cargo.lock;
-          outputHashes = {
-            "mail-builder-0.4.1" = "sha256-1hnsU76ProcX7iXT2UBjHnHbJ/ROT3077sLi3+yAV58=";
-          };
         };
         mkRustPackage = packageName:
           naersk'.buildPackage {